I think Modern surgical pathology and Sternberg/Rosai are all equivalent quick references that hit most major topics. However, I strongly disagree with calling any of these "in-depth knowledge". These will get you to the Dx and give you some relevant information, but are by no means in depth. The foundations series has a lot more information on the given subject, and is as "deep" as a resident needs. Then of course there are the actual "in depth" books for each organ system- these vary from system to system.