31. | | Autor: Maleev, V. L. | |
32. | | Autor: Sporn, Philip | |
33. | | Autor: Macintire, H. J. | |
34. | | Autor: Eshbach, Ovid W. | |
35. | | Autor: Vincent, Edward Thomas | |
36. | | Autor: Lichty, Lester C. | |
37. | | Autor: Fisher, Charles H. | |
38. | | Autor: Bazard, A. | |
39. | | Autor: Stoever, Herman J. Data: 1959 | |
40. | | Autor: Faires, Virgil Moring Data: 1962 | |