目前的情况就是这样。
\begin{thebibliography}{9}
\subsection*{Digitala källor}
\bibliographystyle{ieetr}
\bibitem{Britannica}
''Monte Carlo method,'' i \textit{Britannica}.
[Online]. Tillgänglig: \href {https://www.britannica.com/science/Monte-Carlo-method}{https://www.britannica.com/science/Monte-Carlo-method}, hämtad: 2020-11-15.
\bibitem{SAS}
S.Erlandsson, "Navigation förr och nu, "\textit{Scandinavian traveler}, [Online]. Aug. 2016. Tillgänglig: \href{https://scandinaviantraveler.com/se/flyg/flygnavigation-forr-och-nu}{https://scandinaviantraveler.com/se/flyg/flygnavigation-forr-och-nu}, Hämtad: 2020-11-15.
\bibitem{Simpleflying}
P. Pande, ''How Aircraft navigated before GPS,'' \textit{Simple Flying}, Aug,11, 2020. [Online]. Tillgänglig: \href{https://simpleflying.com/how-aircraft-navigated-before-gps/}{https://simpleflying.com/how-aircraft-navigated-before-gps/}, Hämtad: 2020-11-15.
\bibitem{Bayesian}
N. Bergman, L- Ljung \& F.Gustafsson, ''Terrain Navigation using Bayesian Statistics,'' Linköpings Universitet, Linköping, Sverige, LiTH-ISY-R-2139, 1999. [Online]. Tillgänglig: \href{http://liu.diva-portal.org/smash/get/diva2:316450/FULLTEXT01.pdf}{http://liu.diva-portal.org/smash/get/diva2:316450/FULLTEXT01.pdf}, Hämtad: 2020-11-15.
\bibitem{Marginalized}
T. Schön, F. Gustafsson \& P. J. Nordlund, ''Marginalized Particle Filters for Mixed Linear/Nonlinear State-Space Models,'' \textit{IEEE Transactions on Signal Processing}, vol. 53, nr. 7, ss. 2279-2289, Jul. 2005, doi:10.1109/TSP.2005.849151.
\bibitem{Pi}
U. Singh, ''Estimation of the value of pi using Monte Carlo Method and Related Study of Errors,'' \textit{Mathematics in School}, vol. 42, nr. 5, ss. 21-23, Nov. 2013, Tillgänglig: \href{https://www.academia.edu/1887423/Estimation_of_the_value_of_pi_using_Monte_Carlo_Method_and_Related_Study_of_Errors} {https://www.academia.edu/1887423/Estimation_of_the_value_of_pi_using_Monte_Carlo_Method_and_Related_Study_of_Errors}, Hämtad: 2021-02-26.
\subsection*{Bildkällor}
\setcounter{bibitem}{0}
\bibitem{Bild}
N. Bergman, L- Ljung \& F.Gustafsson, ''Terrain Navigation using Bayesian Statistics,'' Linköpings Universitet, Linköping, Sverige, LiTH-ISY-R-2139, 1999. [Online]. Tillgänglig: \href{http://liu.diva-portal.org/smash/get/diva2:316450/FULLTEXT01.pdf}{http://liu.diva-portal.org/smash/get/diva2:316450/FULLTEXT01.pdf}, Hämtad: 2020-11-15.
\end{thebibliography}
而且效果很好！但我必须将其分成两部分并重置引用计数器。我尝试使用\setcounter但似乎没有任何效果。我更喜欢 BIbTeX biblatex，宁愿不使用它。有什么办法可以解决这个问题吗？