Some Remarks on the Contraction of Groups
A statistical study of pulsating stars. Fourteenth paper: Irregular variables in & Cen
Some results of a spectroscopic study of the atmosphere of 31 Cygni
A statistical study of pulsating stars.Sixth paper: Variables in miscellaneous clusters
A statistical study of pulsating stars.Fourth paper: The variables in Messier 3
A statistical study of pulsating stars. Third paper: The variable stars in Messier 5