Vlasak, J. C. (1952). A statistical study of one hundred cases known to the Shell Guidance Service, Social Service Department, Catholic Youth Organization, Chicago, Illinois, and closed during the period, July, 1949 to January, 1952.

Vlasak, Joseph Charles. A Statistical Study of One Hundred Cases Known to the Shell Guidance Service, Social Service Department, Catholic Youth Organization, Chicago, Illinois, and Closed During the Period, July, 1949 to January, 1952. 1952.

Vlasak, Joseph Charles. A Statistical Study of One Hundred Cases Known to the Shell Guidance Service, Social Service Department, Catholic Youth Organization, Chicago, Illinois, and Closed During the Period, July, 1949 to January, 1952. 1952.