使用 dcu 样式和 natbib，一些引用显示为问号，而其他则不显示。我提供了可以工作的引用示例以及不能像我使用的代码那样工作的引用示例。为什么在生成的报告中列出的不起作用的引用显示为问号 [?]，尽管使用了完全相同的代码？这是序言：
\documentclass[a4paper]{ociamthesis}
\usepackage{natbib, har2nat}
\setcitestyle{authoryear,notesep={:}}
\begin{document}
Some Text with citations
These work with \citep and with \cite
\citep{bertrand_are_2004, bertrand_implicit_2005} \citep{bertrand_field_2016}
\citep{bohren_dynamics_2018}.
\citep{bartelme_luck_2005}
these do not work regardless
\citep{nyquist_what_2014}
\citep{iom_best_2012}
\citep{burke_neuroimaging_2016}
\bibliographystyle{dcu}
\bibliography{references}
\end{document}
使用 Zotero 集成创建的正确生成的参考示例：
@article{bartelme_luck_2005,
title = {Luck or {Skill}? {A}-{Team} {Players} {Don}'t {Get} {Sued}},
volume = {31},
copyright = {Copyright American College of Physician Executives Sep/Oct 2005},
issn = {08982759},
shorttitle = {Luck or {Skill}?},
url = {http://undefined/docview/199986499/abstract/5689B23D75474D34PQ/1},
abstract = {Every year, roughly one out of seven doctors gets sued, and if one is in a high-risk specialty, the odds are particularly grim. Yet some physicians practice year in and year out without ever being slapped with a lawsuit. Accomplished lawsuit-free doctors from across the country were interviewed and it was found that physicians are not necessarily at fate's whim. Using lessons from their own patients, they made their own luck. Strait Fairey, MD, has been a family physician for more than 30 years and says he has not been sued because the Lord looks out for some of them sometimes, and because his communication skills have kept him out of trouble. Donald Pocock, MD, FACP, CPE, has been in practice for 32 years, mostly with a busy internist group in Eastern North Carolina. He has never been sued, but there is not a doctor alive who has not made a mistake or had a bad outcome.},
language = {English},
number = {5},
urldate = {2019-05-09TZ},
journal = {Physician Executive; Tampa},
author = {Bartelme, Tony},
month = oct,
year = {2005},
keywords = {Fate, Health Facilities And Administration, Litigation, Medical malpractice, Physicians, Skills},
pages = {22--6}
}
@article{bertrand_are_2004,
title = {Are {Emily} and {Greg} {More} {Employable} than {Lakisha} and {Jamal}? {A} {Field} {Experiment} on {Labor} {Market} {Discrimination}},
volume = {94},
url = {http://www.jstor.org/stable/3592802},
language = {en},
number = {4,},
journal = {The American Economic Review},
author = {Bertrand, Marianne and Mullainathan, Sendhil},
year = {2004},
pages = {991--1013}
}
@article{bertrand_implicit_2005,
title = {Implicit {Discrimination}},
volume = {95},
issn = {0002-8282},
url = {https://www.aeaweb.org/articles?id=10.1257/000282805774670365},
doi = {10.1257/000282805774670365},
language = {en},
number = {2},
urldate = {2019-04-20TZ},
journal = {American Economic Review},
author = {Bertrand, Marianne and Chugh, Dolly and Mullainathan, Sendhil},
month = may,
year = {2005},
pages = {94--98}
}
@techreport{bertrand_field_2016,
address = {Cambridge, MA},
title = {Field {Experiments} on {Discrimination}},
url = {http://www.nber.org/papers/w22014.pdf},
abstract = {This article reviews the existing field experimentation literature on the prevalence of discrimination, the consequences of such discrimination, and possible approaches to undermine it. We highlight key gaps in the literature and ripe opportunities for future field work. Section 1 reviews the various experimental methods that have been employed to measure the prevalence of discrimination, most notably audit and correspondence studies; it also describes several other measurement tools commonly used in lab-based work that deserve greater consideration in field research. Section 2 provides an overview of the literature on the costs of being stereotyped or discriminated against, with a focus on self-expectancy effects and self-fulfilling prophecies; section 2 also discusses the thin field-based literature on the consequences of limited diversity in organizations and groups. The final section of the paper, Section 3, reviews the evidence for policies and interventions aimed at weakening discrimination, covering role model and intergroup contact effects, as well as socio-cognitive and technological de-biasing strategies.},
language = {en},
number = {w22014},
urldate = {2019-04-22TZ},
institution = {National Bureau of Economic Research},
author = {Bertrand, Marianne and Duflo, Esther},
month = feb,
year = {2016},
doi = {10.3386/w22014},
pages = {w22014}
}
@article{bohren_dynamics_2018,
title = {The {Dynamics} of {Discrimination}: {Theory} and {Evidence}},
url = {https://economics.sas.upenn.edu/system/files/working-papers/18-016%20PIER%20Paper%20Submission.pdf},
abstract = {We model the dynamics of discrimination and show how its evolution can identify the underlying source. We test these theoretical predictions in a field experiment on a large online platform where users post content that is evaluated by other users on the platform. We assign posts to accounts that exogenously vary by gender and evaluation histories. With no prior evaluations, women face significant discrimination. However, following a sequence of positive evaluations, the direction of discrimination reverses: women’s posts are favored over men’s. Interpreting these results through the lens of our model, this dynamic reversal implies discrimination driven by biased beliefs.},
language = {en},
journal = {Penn Institute for Economic Research},
author = {Bohren, J Aislinn and Imas, Alex and Rosenberg, Michael},
month = jul,
year = {2018},
pages = {76}
}
这些参考资料被同时导出但是不起作用：
@article{nyquist_what_2014,
title = {What {Doctors} {Feel}: {How} {Emotions} {Affect} the {Practice} of {Medicine}},
volume = {28},
issn = {1042-5055},
shorttitle = {What {Doctors} {Feel}},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4211592/},
doi = {10.7899/JCE-14-23},
number = {2},
urldate = {2019-05-09TZ},
journal = {The Journal of Chiropractic Education},
author = {Nyquist, Julie G.},
month = oct,
year = {2014},
pmid = {25222631},
pmcid = {PMC4211592},
pages = {173--174}
}
@book{iom_best_2012,
title = {Best {Care} at {Lower} {Cost}: {The} {Path} to {Continuously} {Learning} {Health} {Care} in {America}},
isbn = {978-0-309-26073-2},
shorttitle = {Best {Care} at {Lower} {Cost}},
url = {https://www.nap.edu/catalog/13444/best-care-at-lower-cost-the-path-to-continuously-learning},
abstract = {Download a PDF of "Best Care at Lower Cost" by the Institute of Medicine for free.},
language = {en},
urldate = {2019-04-28TZ},
author = {IOM},
month = sep,
year = {2012},
doi = {10.17226/13444}
}
@article{burke_neuroimaging_2016,
title = {Neuroimaging overuse is more common in {Medicare} compared with the {VA}},
url = {https://n.neurology.org/content/87/8/792},
author = {Burke, James},
month = aug,
year = {2016}
}