APA (7th ed.) Citation

Ridley, E. (2018). Once upon a duke: 12 dukes of christmas, #1. Erica Ridley.

Chicago Style (17th ed.) Citation

Ridley, Erica. Once upon a Duke: 12 Dukes of Christmas, #1. Oklahoma City: Erica Ridley, 2018.

MLA (8th ed.) Citation

Ridley, Erica. Once upon a Duke: 12 Dukes of Christmas, #1. Erica Ridley, 2018.

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