2501
2502
2503
2504
2505
2506
2507
Published: 1896
Superior document: Transactions of the Texas Academy of Science 1,5,[7]
2508
2509
2510
Published: 1978
Superior document: Transactions of the American Philosophical Society 68,1
2511
2512
2513
2514
Published: 1967
Superior document: Acta Universtitatis Stockholmiensis : Stockholms studies in educational psychology 15
2515
2516
2517
2518
Published: 1994
Superior document: Varia 5
2519
2520