APA (7th ed.) Citation

Gentex Corporation. (1969). Instruction manual for the Gentex SPH-4 pilot's protective helmet. Gentex Corporation.

Chicago Style (17th ed.) Citation

Gentex Corporation. Instruction Manual for the Gentex SPH-4 Pilot's Protective Helmet. Carbondale, Pa.: Gentex Corporation, 1969.

MLA (9th ed.) Citation

Gentex Corporation. Instruction Manual for the Gentex SPH-4 Pilot's Protective Helmet. Gentex Corporation, 1969.

Warning: These citations may not always be 100% accurate.