What sources are used in preparing the Topics in our textbook? They include general references (Textbooks, WHO and AFIP/ARP publications, image websites) listed on the Chapter pages, references cited in the Topics, as well as Rosai, Sternberg or Robbins, which were typically the source for early versions of many topics. We list the later editions of these standard textbooks only if they are actually cited by the reviewers. I acknowledge that this policy is a little inaccurate, because we are not giving credit to the original source for material that may not have changed much over the years. On the other hand, we prefer not to list old editions of the source (which won't be useful to pathologists), and we don't want to list a newer edition if the reviewer has not actually consulted it. So, the source for standard information about an entity that hasn't changed in years is likely to be one of these standard textbooks.
We are very careful to respect the copyright of authors. We do not intentionally copy text from authors, or use so much of it that it would violate their copyright. If you are concerned, let us know. However, it is important to understand the limitations of copyright. As noted here, "Copyright does not cover ideas and information themselves, only the form or manner in which they are expressed." Thus, if one summarizes the main points discussed in a textbook or paper, that is NOT a copyright violation, but if one cuts and pastes the text, using the exact same words, that likely is a copyright violation.