APA Citation

Youmans, D., & Youmans, D. (1985). Halley returns. Pasadena, California: Planetary Society.

Chicago Style Citation

Youmans, Dave, and Dave Youmans. Halley Returns. Pasadena, California: Planetary Society, 1985.

MLA Citation

Youmans, Dave, and Dave Youmans. Halley Returns. Pasadena, California: Planetary Society, 1985.

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