Huntley P.
Br Dent J. 1990 Oct 20;169(8):230. doi: 10.1038/sj.bdj.4807338.
PMID: 2245089

Graham JW.
J Am Dent Assoc. 1978 May;96(5):767-71. doi: 10.14219/jada.archive.1978.0171.
PMID: 274491

Turunen S, Vesala H, Nyyssönen V.
Suom Hammaslaakarilehti. 1991 Oct 15;38(18):1244-6.
PMID: 1817321

Sinkford JC.
J Dent Educ. 1969 Mar;33(1):43-58.
PMID: 5249605

Lehtinen R, Murtomaa H.
Suom Hammaslaakarilehti. 1986 Jun 01;33(11):675-7.
PMID: 3462860

White RP, Vanarsdall RL.
Int J Adult Orthodon Orthognath Surg. 1995;10(4):231.
PMID: 9082011

Weaver R.
J Dent Educ. 1999 Aug;63(8):626-34.
PMID: 10478197