Bosnia Herzegovina Postmarks?

Hello all, this is my first post and I'm hoping there might be some Austrian or Bosnia Herzegovina experts hanging around here.

I'm looking for a good reference for the postmarks of Bosnia Herzegovina through 1918. On something of an impulse I recently bought a collection of used BH stamps and the original owner has annotated many of them with the cancellation type. On the coat of arms issues I see many in the 400s followed by a letter (such as 407d).

For the life of me I can't find the source of his numbers. I'm unsure whether the Ferchenbauer, despite its size, covers Bosnian cancels in that sort of depth. Michel perhaps? The only other cancel specific source I've seen mentioned is a long out of print book by someone called TM Gordon "Checklist of Town Cancellations of Bosnia Herzegovnia." I've had no luck finding a copy for sale.

There is a copy of a book on Bosnia postal history 1879 to 1918 on ebay right now, search for the keywords "bosnien Postgeschichte" worldwide. The book seems to be in both German and English. Published in 2006, which is pretty recent and the price seems reasonable. If I collected Bosnia, I would have snapped it up myself.

I found this auction collection; it could be useful perhaps:lot 5277
https://stampauctionnetwork.com/zg/zg728312.cfm

That ebay auction appears to be precisely the thing I need. Now I just hope there are no other BH collectors reading this :-)

As far as the stampauctionnetwork lots, these are along the lines of what I have. Very beautiful issues in my opinion, from the Coat of Arms on through the 1918 issues. As I said, this was something of an impulse but I think they could keep me occupied for a long time.

Thank you both!