Phillips, Edward C., "Second Note on Personal Equation in Observing Occultations" from Popular Astronomy, Vol. XXXVI, No. 7, August-September,, 1928

Phillips, Edward C., "Second Note on Personal Equation in Observing Occultations" from Popular Astronomy, Vol. XXXVI, No. 7, August-September,, 1928. Georgetown Observatory Collection, GRB-000010. Georgetown University Rare Books , Booth Family Center for Special Collections. https://findingaids.library.georgetown.edu/repositories/14/archival_objects/1163548 Accessed December 23, 2025.