A statistical study of pulsating stars.Fifth paper: The variables stars in M 53 and N.G.C. 3201
Some results of a spectroscopic study of the atmosphere of 31 Cygni
A statistical study of pulsating stars.Seventh paper: The variables in M 2
Note On a Generalization of Schwarz' Lemma
The apparent variations of the solar diameter
A statistical study of pulsating stars.second paper: The irregular variable A.R. Her
A statistical study of pulsating stars. Fourteenth paper: Irregular variables in & Cen