Cite

"Songs of 'Porgy'," vocal scores, manuscript (5 copies)

MLA

Guild, Theatre. "Songs of 'Porgy'," Vocal Scores, Manuscript (5 Copies). 0AD. https://collections.library.yale.edu/catalog/17392160.

APA, 6th edition

Guild, T. (0 C.E.). "Songs of 'Porgy'," vocal scores, manuscript (5 copies). https://collections.library.yale.edu/catalog/17392160.