I have a problem identifying what fonts are used in typesetting these pdf documents. However, since I'm a beginner here with low reputation, I can't post an image caption of the files. Even if I could do so, the quality of the image is so low that I'm afraid won't be clear enough in order to identify the fonts correctly. So I managed to upload two examples pdf files in Dropbox and put the links here. I'm sorry if that may cause you any difficulty.
For the first font, the letters look almost the same as the default font of Latex typesetting. However there's a small difference. You can view it in the sample file here. For the second, the letters are slightly fatter. You can view it here.
Any help is greatly appreciated. I really don't know who to ask, because I just encountered the pdf files, not the .tex files, and had no idea what fonts are used.
\usepackage{lmodern}. – mafp Jun 07 '13 at 09:40