• Tehniline mehaanika. 2Maddison, Ottomar1927 https://www.ester.ee/record=b1360107*est
• Tehniline mehaanika. 2Maddison, Ottomar1928 https://www.ester.ee/record=b1382239*est
• Tehniline mehaanika. 2Maddison, Ottomar1927 https://www.ester.ee/record=b1360106*est