APA (7th ed.) Citation

Hillman, D. J. (1964). Mathematical theories of relevance with respect to the problems of indexing. National Science Foundation.

Chicago Style (17th ed.) Citation

Hillman, Donald J. Mathematical Theories of Relevance with Respect to the Problems of Indexing. Bethlehem, Pa.: National Science Foundation, 1964.

MLA (8th ed.) Citation

Hillman, Donald J. Mathematical Theories of Relevance with Respect to the Problems of Indexing. National Science Foundation, 1964.