Using natbib and plainnat - no year appears to some references and also et al. not in Italics

Question

I use natbib and plainnat for bibliography, I use \citep.

1. The reference appears with et al. that is not italics – how do I change that?
2. Some references just appear with no year. How to fix that?
3. When same author and not same year, how do I get rid from the a,b notation of the same author? I tried garynat instead of plainnat and it solved the italics of et al. but still problem with the missing year.

Answer 1

How to typeset "et al." in italics: Copy the file plainnat.bst (located in the \bibtex\bst\natbib subdirectory of your TeX distribution) into your working directory and rename it to, say, myplainnat.bst. (Later, this file should be placed in your local TEXMF tree). In the renamed copy, search for the string " et~al." * (there should be four instances) and replace every instance with " \emph{et~al.}" *. In your .tex file, use \bibliographystyle{myplainnat}.

Your other questions can't be answered without a minimal working example.