Catholic Online: St. Zephyrinus: Very brief biographical sketch.
Pope St. Zephyrinus: Fairly long article on this pontiff, who died in 217.
Pope Zephyrinus: Illustrated profile. His cultus was suppressed in 1969.
Pope Zephyrinus: Brief biography of his decrees, actions, and life.
Popes Through the Ages: St. Zephyrinus: Overview of his pontificate. From the book by Joseph Brusher.
Zephyrinus: Brief biography, by Karen Rae Keck.
Zephyrinus, Pope: Brief biography.