Heinz RL.
N Y State Dent J. 1967 Aug-Sep;33(7):410.
PMID: 5235311

Levine AH.
TIC. 1982 Feb;41(2):13-4, 16.
PMID: 6951318

Okeke IN.
Afr J Lab Med. 2017 Dec 08;6(1):679. doi: 10.4102/ajlm.v6i1.679. eCollection 2017.
PMID: 29435425

Russell BD, Connell SD.
Science. 2010 Jan 08;327(5962):144-5. doi: 10.1126/science.327.5962.144-c.
PMID: 20056872

Scott ME.
J Acad Gen Dent. 1975 Nov-Dec;23(6):5.
PMID: 1065673

[No authors listed]
J Can Dent Assoc. 1991 Aug;57(8):617.
PMID: 1889008

Ryan AJ.
Phys Sportsmed. 1976 Dec;4(12):29. doi: 10.1080/00913847.1976.11948306.
PMID: 29281538