• Concise Oxford Dictionary of Art Terms (2010)
• Everything Art Handbook (2016, Art techniques & tools)
• Handbook of Visual Culture (2012)
• Hutchinson Dictionary of Symbols in Art (2005)
• Oxford Dictionary of Art (2004)
• Oxford Dictionary of Art and Artists (2015)
• Questions Dictionary of Art, 2002
• Universal Principles of Art (2015, 100 Key Concepts)

General

• Art History: The Key Concepts (2006)
• Getty Research Portal (Current) - "A free online search platform providing worldwide access to an extensive collection of digitized art history texts from a range of institutions." 

Ancient (to A.D. 500)

• Encyclopedia of the History of Classical Archaeology (2015)
• Handbook of Greek Sculpture (2019)
• Oxford Companion to Classical Civilization (2014)

Medieval (500-1550)

• Medieval Art: A Topical Dictionary (1996)
• Oxford Dictionary of Byzantium (2005, use the "search within" feature on the term "Art")

Renaissance (1400-1600)

• Historical Dictionary of Renaissance Art (2016)

Baroque (1600-1725)

• Historical Dictionary of Baroque Art and Architecture (2018)

Rococo (1720-1760)

• Historical Dictionary of Rococo Art (2011)

Neoclassical (1760-1830)

• Historical Dictionary of Neoclassical Art and Architecture (2011)

Romanticism (1800-1850)

• Historical Dictionary of Romanticism in Literature (2014) Use "search within" for articles on Romantic Art

1800-Present

• Dictionary of Modern & Contemporary Art (Oxford) 
• Edinburgh Dictionary of Modernism (2015)
• Historical Dictionary of Contemporary Art (2016)
• Historical Dictionary of Surrealism (2010)
• Oxford Companion to Western Art (2001)

Women in Art

• Concise Dictionary of Women Artists (2001)
• Frontier Women and Their Art : A Chronological Encyclopedia (2018)

• Dictionary of Islamic Architecture (1996)
• Dutch Art: An Encyclopedia (1997)
• Encyclopedia of American Folk Art (2004)
• New Encyclopedia of Southern Culture, v. 21: Art and Architecture (2013)
• New Encyclopedia of Southern Culture, v. 23: Folk Art (2013)
• Oxford Companion to Western Art (2001)
• Oxford Dictionary of American Art and Artists (2007)

• A-Z of Animation and Cartoons (2009)
• Animator's Reference Book (2005)
• Anime Encyclopedia (2015)
• Ceramic Art: Innovative Techniques (2009, Handbook)
• Dictionary of Architecture & Landscape Architecture (2006, Oxford) 
• Encyclopedia of Black Comics (2017)
• Encyclopedia of Creativity (2011)
• Handbook of Art Therapy and Digital Technology (2018)
• Hutchinson Dictionary of Symbols in Art (2005)

• Focal Encyclopedia of Photography (2007)
• Oxford Companion to the Photograph (2005)
• Photography and the Art Market (2018)

• Design Dictionary : Perspectives on Design Terminology (2007)
• Dictionary of Modern Design (2004)
• Graphic Design (2010, compilation of more than 200 of the most common terms)
• Language of Graphic Design Revised and Updated (2018, Handbook)
• Typography, referenced: a comprehensive visual guide to the language, history, and practice of typography (2012)
• Universal Principles of Design (2010)