Hale, George E. (1926) Visual observations of the solar atmosphere; Proceedings of the National Academy of Sciences of the United States of America; Vol. 12; No. 5; 286-295
Hale, George E. (1924) The spectrohelioscope; Proceedings of the National Academy of Sciences of the United States of America; Vol. 10; No. 8; 361-363
Hale, George E. (1924) The law of sun-spot polarity; Proceedings of the National Academy of Sciences of the United States of America; Vol. 10; No. 1; 53-55
Hale, George E. (1922) Invisible sun-spots; Proceedings of the National Academy of Sciences of the United States of America; Vol. 8; No. 7; 168-170
Pickering, Edward C. and Campbell, W. W., et el. (1917) Report of the Astronomy Committee; Proceedings of the National Academy of Sciences of the United States of America; Vol. 3; No. 6; 444-446
Hale, George E. and Ellerman, Ferdinand (1916) The Minute Structure of the Solar Atmosphere; Proceedings of the National Academy of Sciences of the United States of America; Vol. 2; No. 2; 102-109