Clarifying the latent structure and correlates of somatic symptom distress: A bifactor model approach
Psychological Assessment (2016) - Comment
pubmed: 26029944  doi: 10.1037/pas0000150  issn: 1939-134x  issn: 1040-3590 

Michael Witthöft, Susanne Fischer, Fabian Jasper, Fred Rist, Urs M. Nater