diff --git a/sources.tex b/sources.tex
index 5799292..6bd05fb 100644
--- a/sources.tex
+++ b/sources.tex
@@ -25,4 +25,5 @@
    \bibitem{links:scipy_doc} Scipy API Reference [Электронный ресурс] -- URL:~\url{https://docs.scipy.org/doc/scipy/reference/index.html} (\LiteratureAccessDate[3]).
    \bibitem{links:tiobe_index} TIOBE. Официальный сайт проекта
    [Электронный ресурс] -- URL:~\url{https://www.tiobe.com/tiobe-index/} (\LiteratureAccessDate).
+   \bibitem{journal:cartwright} Simpson's Rule Cumulative Integration with MS Excel and Irregularly-spaced Data / Cartwright, Kenneth V.  // Journal of Mathematical Sciences and Mathematics Education. -- Vol.~12 --  P.~1-9
 \end{thebibliography}