George L. Engel (6 July 2009)۔ "The Need for a New Medical Model: A Challenge for Biomedicine"۔ Holistic Medicine۔ 4 (1): 37–53۔ doi:10.3109/13561828909043606
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ncbi.nlm.nih.gov
GL Engel (8 April 1977)۔ "The need for a new medical model: a challenge for biomedicine."۔ Science۔ 196 (4286): 129–36۔ PMID847460