Crawford, R. T. (1915). "Address upon the Presentation of the Bruce Gold Medal to Dr. W. W. CAMPBELL". Publications of the Astronomical Society of the Pacific. 27 (160): 153. Bibcode:1915PASP...27..153C. doi:10.1086/122422. S2CID123267305.
Crawford, R. T. (1915). "Address upon the Presentation of the Bruce Gold Medal to Dr. W. W. CAMPBELL". Publications of the Astronomical Society of the Pacific. 27 (160): 153. Bibcode:1915PASP...27..153C. doi:10.1086/122422. S2CID123267305.
Campbell, W. W. (1928). "Observations made with a pair of five-foot cameras on the light- deflections in the Sun's gravitational field at the total eclipse of September 21, 1922". Lick Observatory Bulletin. 397: 160.[2]
Crawford, R. T. (1915). "Address upon the Presentation of the Bruce Gold Medal to Dr. W. W. CAMPBELL". Publications of the Astronomical Society of the Pacific. 27 (160): 153. Bibcode:1915PASP...27..153C. doi:10.1086/122422. S2CID123267305.