Esquire Drinks, An Opinionated & Irreverent Guide to Drinking - David Wondrich (out of print, but is available used on Amazon for as little as $2.81!) An old book - 2002, but a goodie. Mr. Wondrich, who is the end all authority on cocktail history wrote this book for Esquire Magazine. If you ever want the definitive answer on the history of a cocktail, just google the name of the drink and "Wondrich". (He was a guest on Episode 110.)
Regarding Cocktails - Sasha Petraske (Foreword by Dale DeGroff), Shsah changed everything in our industry. (He's NOT been a guest on the show, he unfortunately passed away in 2015... I never had the opportunity to meet the man, but he influenced so many).
Cocktails Made Simple: Easy & Delicious Recipes for the Home Bartender by Brian Weber and Amin Benny. What to make cocktails at home, or get a foundation for becoming a professional Bartender? This book is authored by host of Bartender Journey, Brian Weber and co-author Amin Benny.