Keen, G. (1971). The sale of works of art: A study based on the Times-Sotheby Index. Nelson.
Citazione stile Chigago Style (17a edizione)Keen, Geraldine. The Sale of Works of Art: A Study Based on the Times-Sotheby Index. [London]: Nelson, 1971.
Citatione MLA (9a ed.)Keen, Geraldine. The Sale of Works of Art: A Study Based on the Times-Sotheby Index. Nelson, 1971.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.