Chen M., Andersen RM, Barmes DE, Leclercq M-H., Lyttle CS (1997). Comparing oral health care systems. Geneva: World Health Organization.
2.
Schwarz E., Zhang HG, Wang ZJ, Lin HC, Lo Ecm, Corbet EF, et al. (2001). An oral health survey in southern China, 1997. J Dent Res80(Spec Sect): 1451-1495.
