APA (7th ed.) Citation

Larkins, F., Larkins, F. P., & Coulson, C. (1969). Problems concerning the electonic structure of solids.

Chicago Style (17th ed.) Citation

Larkins, F., Francis Patrick Larkins, and C. Coulson. Problems Concerning the Electonic Structure of Solids. 1969.

MLA (9th ed.) Citation

Larkins, F., et al. Problems Concerning the Electonic Structure of Solids. 1969.