"Case 3: Helen Gardner". The Art Institute of Chicago. Chicago. 2013. Retrieved March 14, 2017.
britannica.com
The Editors of Encyclopædia Britannica (August 17, 2016). "Helen Gardner". Encyclopaedia Britannica. Retrieved March 14, 2017. {{cite web}}: |last1= has generic name (help)
doi.org
Kader, Themina (2000). "The Bible of Art History: Gardner's Art Through the Ages". Studies in Art Education. 41 (2): 164–177. doi:10.2307/1320661. JSTOR1320661. S2CID164953403.
jstor.org
Kader, Themina (2000). "The Bible of Art History: Gardner's Art Through the Ages". Studies in Art Education. 41 (2): 164–177. doi:10.2307/1320661. JSTOR1320661. S2CID164953403.
semanticscholar.org
api.semanticscholar.org
Kader, Themina (2000). "The Bible of Art History: Gardner's Art Through the Ages". Studies in Art Education. 41 (2): 164–177. doi:10.2307/1320661. JSTOR1320661. S2CID164953403.