John W. Ritchie, Chapin W. Day & Pearl A. Ritchie.
Biology and human affairs; shorter course, revised.
R587227. Biology and human affairs; shorter course, revised. By John W. Ritchie, Chapin W. Day & Pearl A. Ritchie. NM: additions & revisions. © 15Oct46; A11876. Margaret Ritchie (C of Pearl A. Ritchie); 7Oct74; R587227.
Margaret Ritchie|C of Pearl A. Ritchie