| Source: Mercantile and Manufacturing Scrapbooks, circa 1948-1977 Location: Reading Room / St.L. / 658 / M533 | |
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| Corporate Name: | Hellmuth, Obata & Kassabaum |
| Volume: | 3 |
| Page: | 215 |
| Remarks: | noted as architects in article titled "Ralston Purina to Build 8-Story Office Building, Research Unit," 1966 |
