"Harrington on Online Cash Games: 6-Max No-Limit Hold 'em" by Bill Robertie is a comprehensive textbook published by Two Plus Two Publishing, LLC in 2010. The book, with 600 pages, offers in-depth instruction on the popular online cash game variant of 6-max no-limit hold 'em. Written in English by renowned authors Daniel Harrington and Bill Robertie, this mass-market paperback covers various aspects of the game, making it a valuable resource for both beginners and experienced players looking to improve their online poker skills.