Cite

16. [Engelmann Spruce ( Picea engelmannii).]

MLA

McClintock, Walter, 1870-1949. 16. [Engelmann Spruce ( Picea engelmannii).]. Box 60, folder 2943. 1941. https://collections.library.yale.edu/catalog/2008359.

APA, 6th edition

McClintock, Walter, 1870-1949. (["Box 60, folder 2943"])(1941)[16. [Engelmann Spruce ( Picea engelmannii).]]. https://collections.library.yale.edu/catalog/2008359.