Porsius, JTMartens, ALSlottje, PClaassen, LKorevaar, JCTimmermans, DRMVermeulen, RSmid, T2025-03-252025-03-2520152652631210.1016/j.jpsychores.2015.09.006https://rivm.openrepository.com/handle/10029/649058Somatic symptom reports in the general population: Application of a bi-factor model to the analysis of changeArticleJ Psychosom Res 2015; 79(5):378-832025-03-25