edited books
If you import data from RefMan databases or from internetsites there occurs a problem with the right label at edited books. I tested it with a RefMan Database (via export as RIS-file) and with the import from the amazon homepage. At bookchapters or at edited books the editor gets the wrong label (as author or Mitarbeiter (in the german version)). When you create a bibliography this problem will make trouble. I didnt check if there is the same problem with other webpages or Endnote databases but it seems to be a systematic problem.
Download a BibTeX output style from the web, often you must modify the output style via the tool in RefMan (this is the crucial point ;-) ), generate a bibliography in RefMan via the modified output style in a txt-file (do not use the export-tool!), than you can import the txt-file (BibTeX format) into Cotero. I did some modification at the output style that I found in the web and it worked well – but I create the output style for only four reference types (book, book chapter, journal article and thesis).