1. Le Chatelier, H., Ann. Phys. 2 (1887) 351
2. Barus, C., Bull. USA, Geological Survey 54 (1889)
3. Pouillet, C. S. M., Compt. rend. 3 (1836) 786
4. Roeser, W. F., J. Appl. Phys. 11 (1940) 388
5. Lück, W., VDI-Ber. 112, Techn. Temper. Mess., Düsseldorf 1966