APA (7th ed.) Citation

Hatmaker, P. (1931). Diatomite as filler in battery boxes. [publisher not identified].

Chicago Style (17th ed.) Citation

Hatmaker, Paul. Diatomite as Filler in Battery Boxes. Washington, D.C.: [publisher not identified], 1931.

MLA (9th ed.) Citation

Hatmaker, Paul. Diatomite as Filler in Battery Boxes. [publisher not identified], 1931.