4) Bossy, J., Chevalier, J.M. and Sambuc, P. : In vitro survey of low energy laser beam penetration in compact bone. Acupuncture & Electro-Therapeutic Res., Int. J., 10 : 35~39, 1985.
5) LaPlant, M., Parker, J., Stewart, B., Waner, M. and Straight, R.C : Comparison of the optical transmission properties of pulsed and continuous wave light in biological tissue, Laser in Surgery and Medicine 7 : 336~338, 1987.