1
2
3
Published: 1940
Superior document: Publications of the Observatory of the University of Michigan 8,4
4
Published: 1937
Superior document: Publications of the Observatory of the University of Michigan 7,1
5
6
Published: 1933
Superior document: Publications of the Observatory of the University of Michigan 5,10
7
8
Published: 1934
Superior document: Publications of the Observatory of the University of Michigan 6,4
9
Published: 1939
Superior document: Publications of the Observatory of the University of Michigan 7,9
10
Published: 1935
Superior document: Publications of the Observatory of the University of Michigan 6,8
11
Published: 1931
Superior document: Publications of the Observatory of the University of Michigan 4,4