Volpintesta EJ.
Conn Med. 1992 Dec;56(12):707.
PMID: 1288939

Navarro V.
Int J Health Serv. 2015;45(4):585-6. doi: 10.1177/0020731415603875. Epub 2015 Sep 01.
PMID: 26333817

[No authors listed]
Lancet. 1953 May 23;1(6769):1048-50.
PMID: 13045520

Bauchner H, Easley TJ.
JAMA. 2020 Jan 28;323(4):318. doi: 10.1001/jama.2019.19691.
PMID: 31830206

Filstead WJ.
Health Policy Q. 1981;1(1):43-56.
PMID: 10251984

Peniston RL.
J Natl Med Assoc. 1989 Oct;81(10):1027-9.
PMID: 2810390

Hillman BJ.
J Am Coll Radiol. 2009 Mar;6(3):135-6. doi: 10.1016/j.jacr.2008.11.023.
PMID: 19248985