Gambit repertoire books

Alterman Gambit Guide by Boris Alterman. This is a 3-volume series in which the author offers a select gambit repertoire for both White and Black. The treatment of the gambits covered is quite instructive. The first volume covers White gambits (G.) as follows: Danish G., Urusov G., Cochran G., Evans G., Morra G., and the Milner-Barry G.. Several other openings are covered including the Morphy Attack vs the Two Knights Defense, the Max Lange Attack and the Panov-Botvinnik Attack. The second volume features Black Gambits against 1.d4 and 1.c4, primarily the Benko G., Blumenfeld G. and Vaganian G.. The third volume continues with Black Gambits against 1.e4 and 1.f4 - The Marshall Attack, Hector G., Traxler Counterattack, Frankenstein-Dracula G., Falkbeer Counter G., and From's G. See also "Open Gambits" by George Botterill.
https://www.qualitychess.co.uk/ebooks/Alterman-Gambit-Guide.pdf
https://www.qualitychess.co.uk/ebooks/Black-Gambits-1-exceprt.pdf
https://www.qualitychess.co.uk/ebooks/Black-Gambits-2-excerpt.pdf
A site devoted to gambits: http://www.ianchessgambits.com/