# amsthm and citations using natbib [duplicate]

The standard way of combining a citation with the amsthm package is to use :

\begin{thm}[\citep{...}].


However, suppose I want to name a particular theorem I am referencing. If we were outside the amsthm environment, we could just use \citep[Theorem blah]{...}, but attempting to do this in amsthm creates errors, i.e. :

\begin{thm}[\citep[Theorem blah]{...}]


does not work. Are there any ways to get around this?

• Welcome to TeX.SX! This has already been asked: you have to brace \citep: \begin{thm}[{\citep[Theorem blah]{key}}]; the linked question has \cite, but it's the same problem. – egreg Jul 15 '14 at 15:09
• Apologies for the double post (I did try to look beforehand), and thanks for the help. – user59132 Jul 15 '14 at 15:29
• No problem: searching on the site is not always easy if you don't know the right keys: I looked for "theorem cite" and was lucky. Welcome again! – egreg Jul 15 '14 at 15:34