To convert my .PDFs into Kindle format I just email my Kindle account. I tried one that was in Spanish and words like matemática appear as mate´matica, which is uncomfortable to read.
Is there some way to get the words with correct punctuation? Is it also possible for characters like partial derivatives and integrals?
Converting from PDFs is very difficult task and depends on vary of factors. The short answer is that sending it over Amazon with different parameters (subjects) wont help.
Every PDF file can be saved in different ways. As Images(then you need OCR) or as text layers. If text layers it can be with different coding and sometimes that coding is not same as text in reality is. That makes a lot of troubles. Your problem can be caused by not perfect Amazon OCR system.
You can try to convert it manually by PDFtoEPUB software and then from ePub to kindle by kindlegen software but this will take a long time to do it properly.
