The Oxford Companion to American Theatre by 
The Oxford Companion to Theatre and Performance by 
The Oxford Encyclopedia of Theatre and Performance by 
The Routledge Companion to African American Theatre and Performance by The Routledge Companion to African American Theatre and Performance is an outstanding collection of specially written essays that charts the emergence, development, and diversity of African American Theatre and Performance—fromthe nineteenth-century African Grove Theatre to Afrofuturism. Alongside chapters from scholars are contributions from theatre makers, including producers, theatre managers, choreographers, directors, designers, and critics. This ambitious Companion includes: A "Timeline of African American theatre and performance."
The Routledge Dictionary of Performance and Contemporary Theatre by The Routledge Dictionary of Contemporary Theatre and Performance provides the first authoritative alphabetical guide to the theatre and performance of the last 30 years. Conceived and written by one of the foremost scholars and critics of theatre in the world, it literally takes us from Activism to Zapping, analysing everything along the way from Body Art and the Flashmob to Multimedia and the Postdramatic. What we think of as 'performance' and 'drama' has undergone a transformation in recent decades. Similarly how these terms are defined, used and critiqued has also changed, thanks to interventions from a panoply of theorists from Derrida to Ranciere.
The Routledge Introduction to Theatre and Performance Studies by Erika Fischer-Lichte's introduction to the discipline of Theatre and Performance Studies is a strikingly authoritative and wide ranging guide to the study of theatre in all of its forms. Its three-part structure moves from the first steps in starting to think about performance, through to the diverse and interrelated concerns required of higher-level study:Part 1 - Central Concepts for Theatre and Performance Research - introduces the language and key ideas that are used to discuss and think about theatre: concepts of performance; the emergence of meaning; and the theat.