Jacobs RM.
J Am Coll Dent. 1978 Jul;45(3):139-51.
PMID: 278794

Carroll RG.
Adv Physiol Educ. 2012 Dec;36(4):233. doi: 10.1152/advan.00127.2012.
PMID: 23209001

Ries AL, Kreit LH, Podshadley DW.
J Dent Educ. 1971 Aug;35(8):493-5.
PMID: 5284918

Goulet C.
Nurs Pap. 1983;15(4):43-57.
PMID: 6561525

Mares J.
Sb Ved Pr Lek Fak Karlovy Univerzity Hradci Kralove Suppl. 1980;23(5):657-64.
PMID: 6972592

Schwab T, Karns P.
Nurs Outlook. 1986 Jul-Aug;34(4):208.
PMID: 3637788

Nardiello CA.
Penn Dent J (Phila). 1976;78(3):66-7.
PMID: 71703