Allen, John H., Buck, Roy C. and Wink, A.T.: "Pulling up stakes and breaking apron strings." Agric. Exper. Station, Progress Report No. 136, University Park, Pa., Penna. State University, 1955.
2.
Allen, John H.: Selectivity in the Occupational and Spatial Mobility of Pennyslvania Rural Youth, 1947-1951. Dissertation Abstract (1955), Ann Arbor, Mich., University Microfilms, 1956 .
Mezey, A.G.: "Psychiatric aspects of human migrations." Int. J. Soc. Psychiat.5: 246, 1960.
9.
Murphy, H.B.M.: "Migration and the major mental disorders: a reappraisal." In Mobility and Mental Health, Kantor, M. B., ed., Springfield, Ill.: Charles C. Thomas , 1965.
10.
Odegaard, O. : "Emigration and insanity." Acta Psychiat. et Neurol., Suppl. 4, 1932.
11.
Odegaard, O. : "The distribution of mental diseases in Norway." Acta Psychiat. etNeurol.20: 247, 1945.