| Sobeck, Sylvester; 1949 Blue Book; 1949 | 1949 Blue Book | 1949-00-00 | T. W. ROBINSON | Third Assistant |
| Sobeck, Sylvester; 1966 Red Book; 1965 | 1966 Red Book | 1965-00-00 | W. F. WHITE | Chief Engineer |
| Sobeck, Sylvester; 1967 Red Book; 1967 | 1967 Red Book | 1967-00-00 | W. F. WHITE | Chief Engineer |
| Sobeck, Sylvester; 1967 Red Book; 1967 | 1967 Red Book | 1967-00-00 | T. W. ROBINSON | Chief Engineer |
| Sobeck, Sylvester; 1968 Red Book; 1968 | 1968 Red Book | 1968-00-00 | W. F. WHITE | Chief Engineer |
| Sobeck, Sylvester; 8/48 Great Lakes Review; 1948 | 8/48 Great Lakes Review | 1948-00-00 | CALCITE | Third Assistant |
| Sobeck, Sylvester; Great Lakes News 5/42; 1942 | Great Lakes News 5/42 | 1942-00-00 | CALCITE | Third Assistant |
| Sobeck, Sylvester; Great Lakes News 8/40; 1940 | Great Lakes News 8/40 | 1940-00-00 | CALCITE | Third Assistant |