1993, Chronic pain in a geographically defined general population: studies of differences in age, gender, social class, and pain localization

Andersson HI, Ejlertsson G, Leden I, Rosenberg C

Clin J Pain. 1993 Sep;9(3):174-82

https://www.ncbi.nlm.nih.gov/pubmed/8219517?dopt=Abstract