1. The intensity variation of the green coronal line 1943–1950;Behr;Z. Ap.,1951
2. Bell, B., and Glazer, H. (1953). Comparison of annual intensities of coronal emission lines. Harv. Solar Sci. Rept. No. 12.
3. The shape of coronal line profiles;Billings;Ap. J.,1964
4. Line-width temperatures of distinct coronal features;Billings;Ap. J.,1962
5. Observations of zodiacal light from a very high altitude station. II;Blackwell;M. N.,1961