Start with high-confidence public relations books, then narrow by subgenre or adjacent topics.
The Fall of Advertising and the Rise of PR
Al Ries, Laura Ries
Starring You!
Marta Tracy, Terence Noonan
Guerrilla P.r. 2.0
Michael Levine
The New Community Rules
Tamar Weinberg
Sport Public Relations
G. Clayton Stoldt, Stephen W. Dittmore
Strategic Sport Communication
Paul M. Pedersen, Pamela C. Laucella
Buzzmarketing
Mark Hughes
Trust Me, I'm Lying
Ryan Holiday
Media Relations in Sport
Craig Esherick, Philip H Caskey