I use the "ecta" bibliography style and it works fine for one exception. I have many different citations that include more than 2 authors. However, there is only one citation latex is using the names of all authors instead of abbreviating it with et al.. I use the following command:
\citep[p.~37]{james2013introduction}
And the entry in the bib-file is as follows:
@book{james2013introduction,
title={An Introduction to Statistical Learning},
author={James, Gareth and Witten, Daniela and Hastie, Trevor J. and Tibshirani, Robert John},
year={2013},
publisher={Springer}
}
And I get the following citation in the text:
(James, Witten, Hastie, and Tibshirani, 2013: p. 37)
I tried to change the entry in the bib-file in many different ways. However, I couldn't figure out a way to solve this problem and would very much appreciate some help.
PS: The following is the exact code I am using in my file (calling the bib-file scholar):
\documentclass[12pt,a4paper,fleqn]{article}
\usepackage[round,longnamesfirst,authoryear]{natbib}
\begin{document}
This citation causes the problem: \citep[p.~37]{james2013introduction}
\bibliographystyle{ecta}
\bibliography{scholar.bib}
\end{document}

.bib(but you need to check that no further entries are needed) but we lack a complete example we can copy-paste-compile to reproduce the issue. – cfr Jan 19 '16 at 00:27