Lorenz, Karl A.; Sherbourne, Cathy D.; Shugarman, Lisa R.; Rubenstein, Lisa V.; Wen, Li; Cohen, Angela; Goebel, Joy R.; Hagenmeier, Emily; Simon, Barbara (1 במאי 2009). "How Reliable is Pain as the Fifth Vital Sign?". J Am Board Fam Med. 22 (3): 291–298. doi:10.3122/jabfm.2009.03.080162. PMID19429735. {{cite journal}}: (עזרה)
Lorenz, Karl A.; Sherbourne, Cathy D.; Shugarman, Lisa R.; Rubenstein, Lisa V.; Wen, Li; Cohen, Angela; Goebel, Joy R.; Hagenmeier, Emily; Simon, Barbara (1 במאי 2009). "How Reliable is Pain as the Fifth Vital Sign?". J Am Board Fam Med. 22 (3): 291–298. doi:10.3122/jabfm.2009.03.080162. PMID19429735. {{cite journal}}: (עזרה)