The following books have significant coverage of The Blumenfeld Gambit....(I own all of the following books)...
this is the only book that I know of devoted entirely to the Blumenfeld Gambit...
The Blumenfeld Gambit by Jan Przewoznik & Malcom Pein.....
https://www.amazon.com/Blumenfeld-Gambit-Cadogan-Chess-Books/dp/0080371337/ref=tmm_pap_swatch_0?_encoding=UTF8&qid=1590927877&sr=1-1
the following three books have significant coverage of the Blumenfeld and related gambits...
Alterman Gambit Guide - Black Gambits 1 by Boris Alterman.....(chapter 2)...
https://www.amazon.com/Alterman-Gambit-Guide-Black-Gambits/dp/1906552541/ref=sr_1_2?dchild=1&keywords=alterman+gambit+guide+black+gambits&qid=1590928327&s=books&sr=1-2
http://www.qualitychess.co.uk/ebooks/Black-Gambits-1-exceprt.pdf
Attack With Black by Valery Aveskulov....(chapters 4 & 5)...
https://www.amazon.com/Attack-Black-Valery-Aveskulov/dp/1906454396/ref=tmm_pap_swatch_0?_encoding=UTF8&qid=1590928711&sr=1-1
The following book is from White's perspective...
Squeezing the Gambits: The Benko, Budapest, Albin and Blumenfeld by Kiril Georgiev....(part/chapter 6)....
https://www.amazon.com/Squeezing-Gambits-Benko-Budapest-Blumenfeld/dp/9548782758/ref=sr_1_1?crid=1LSQ1I16SU25U&dchild=1&keywords=squeezing+the+gambits&qid=1590928854&s=books&sprefix=squeezing+the+gambits%2Cstripbooks%2C212&sr=1-1
Good Chess Openings Books For Beginners and Beyond...
https://www.chess.com/blog/RussBell/good-chess-openings-books-for-beginners-and-beyond
Do you know any Blumfeld gambit books?