Just to point out that I have just published a book written 50% with a friend of mine, Roberto Gonzalez, from Renacimiento (he is MVP in Biztalk).
César de la Torre (Architect Evangelist - Microsoft)
Roberto González (MVP Biztalk)
Editorial Krasis Press
Take into account it is written in Spanish, as there are not so many technical books written in Spanish. You can take a look here: