The AMA Manual section 3.13.10 states:
Reference may be made to one author’s citation of, or quotation from, another’s work. Distinguish between citation (work mentioned) and quotation (words actually quoted). In the text, the name of the original author, rather than the secondary source, should be mentioned.
Citation of the original document is preferred unless it is not readily available. Only items actually consulted should be listed.
1. Cauley JA, Lui L-Y, Ensrud KE, et al. Osteoporosis and fracture risk in women of different ethnic groups. JAMA. 2005;293(17):2102-2108. Cited by: Acheson LS. Bone density and the risk of fractures: should treatment thresholds vary by race [editorial]? JAMA. 2005;293(17):2151-2154.
2. Kato S, Sherman PM. What is new related to Helicobacter pylori infection in children and teenagers? Arch Pediatr Adolesc Med. 2005;159(5):415-421. Quoted by: Prazar G. How many pediatricians does it take to change a practice? or how to incorporate change into practice [editorial]. Arch Pediatr Adolesc Med. 2005;159(5):500-502.
3. Groups ask Canada to ban Web pharmacies [press release]. New York, NY: Associated Press; March 30, 2004.