MLA

Brown, Theophilus, and Thom Gunn. Unsought Intimacies : Poems of 1991 / Thom Gunn ; Three Etchings, Theophilus Brown. Peter Koch, Printer, 1993. https://collections.library.yale.edu/catalog/10686724.

APA, 6th edition

Brown, T., & Gunn, T. (1993). Unsought intimacies : poems of 1991 / Thom Gunn ; three etchings, Theophilus Brown. [Etchings (prints), illustrations (AAT)]. Peter Koch, Printer, https://collections.library.yale.edu/catalog/10686724.