Cite Them Right 11th edition - Harvard

Cay S. Horstmann and Cay S. Horstmann (2020) Core Java : Fundamentals, Volume 1.

Chicago Manual of Style 17th edition (full note)

Cay S. Horstmann, and Cay S. Horstmann. Core Java : Fundamentals, Volume 1.

American Psychological Association 7th edition

Cay S. Horstmann, & Cay S. Horstmann. (2020). Core Java : Fundamentals, Volume 1.

Modern Language Association 9th edition

Cay S. Horstmann, and Cay S. Horstmann. Core Java : Fundamentals, Volume 1. 2020.

ISO-690 (author-date, Deutsch)

CAY S. HORSTMANN and CAY S. HORSTMANN, 2020. Core Java : Fundamentals, Volume 1

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