1. Between the Planets;Watson,1941
2. Meteors;Olivier,1925
3. Die Meteore;Hoffmeister,1937
4. The Arizona expedition for the study of meteors;Shapley;Proc, Nail. Acad. Sci. U. S.,1932
5. Öpik, E. (1934). Results of the Arizona expedition for the study of meteors. II. Statistical analysis of group radiants. Circ. Harvard Coll. Obs., No. 388, 38pp.