APA (7th ed.) Citation

Shapley, H. (1919). Studies based on the colors and magnitudes in stellar clusters. s.t.

Chicago Style (17th ed.) Citation

Shapley, Harlow. Studies Based on the Colors and Magnitudes in Stellar Clusters. Washington: s.t, 1919.

MLA (9th ed.) Citation

Shapley, Harlow. Studies Based on the Colors and Magnitudes in Stellar Clusters. s.t, 1919.