Held, Julius S. (December 1991). "Constantijn Huygens and Susanna van Baerle: A Hitherto Unknown Portrait". The Art Bulletin. 73 (4): 653–668. doi:10.2307/3045835. JSTOR3045835.
Held, Julius S. (December 1991). "Constantijn Huygens and Susanna van Baerle: A Hitherto Unknown Portrait". The Art Bulletin. 73 (4): 653–668. doi:10.2307/3045835. JSTOR3045835.