The Bluebook: Uniform System of Citation (21st Edition) Spiral is a textbook published by the Harvard Law Review Association in 2020. Written by the Columbia Law Review, this trade paperback book is a comprehensive guide on legal citation in English. It serves as a valuable resource for students and professionals in the field of law, providing a detailed system of citation rules and guidelines for academic and professional writing in legal contexts. With its focus on education and law, The Bluebook is a must-have for anyone seeking to enhance their understanding of legal citation practices.