APA (7th ed.) Citation

Quilter, R., Allen, T. S., & Parsons, G. Now sleeps the crimson petal.

Chicago Style (17th ed.) Citation

Quilter, Roger, Thomas Sir Allen, and Geoffrey Parsons. Now Sleeps the Crimson Petal.

MLA (9th ed.) Citation

Quilter, Roger, et al. Now Sleeps the Crimson Petal.