Start with high-confidence playwriting books, then narrow by subgenre or adjacent topics.
Poetics
Aristotle, Malcolm Heath
In Shakespeare's Shadow
Michael Blanding
24 Favorite One Act Plays
Bennett Cerf, Van H. Cartmell
Detroit '67
Dominique Morisseau
Plays on Women
Kathleen E. McLuskie, David Bevington
The Malcontent
George Hunter, George K. Hunter
Antonio's Revenge
John Marston, W. Reavley Gair
Philaster: or Love Lies A-bleeding
Andrew Gurr, Francis Beaumont
Epicene, or the Silent Woman
Richard Dutton
Every Man Out of His Humour
Helen Ostovich, Ben Jonson
Galatea
John Lyly, Leah Scragg
The Greek Plays
Sophocles, Aeschylus
Stages of Power
Eric S. Mallin, Paul V. Sullivan
Fairview
Jackie Sibblies Drury
The Way of the World
William Congreve
Salome
Oscar Wilde