APA (7th ed.) Citation

Wielen, R. (1972). On the lifetimes of galactic clusters. Gravitational N-body problem.

Chicago Style (17th ed.) Citation

Wielen, Roland. "On the Lifetimes of Galactic Clusters." Gravitational N-body Problem 1972.

MLA (9th ed.) Citation

Wielen, Roland. "On the Lifetimes of Galactic Clusters." Gravitational N-body Problem, 1972.

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