Notebook, "in which the play was incubated and many of its scenes sketched out roughly"
MLA
MacLeish, Archibald, 1892-1982. Notebook, "in which the play was incubated and many of its scenes sketched out roughly". Box 5, folder 69. n.d.. https://collections.library.yale.edu/catalog/16580270.
APA, 6th edition
MacLeish, Archibald, 1892-1982. (["Box 5, folder 69"])(n.d.)[Notebook, "in which the play was incubated and many of its scenes sketched out roughly"]. https://collections.library.yale.edu/catalog/16580270.