Scott Graham R, Samsell BJ, Proffer A, Moore MA, Vega RA, Stary JM, Mathern B. Evaluation of glycerol-preserved bone allografts in cervical spine fusion: a prospective, randomized controlled trial. J Neurosurg Spine. 2015 Jan;22(1):1-10. doi: 10.3171/2014.9.SPINE131005
Smith VK, Evans MF, Banzhaf HS, Poulos C. Can weak substitution be rehabilitated? Environ Resour Econ (Dordr). 2010 Feb 1;45(2):203-21.
Mansfield CA. Despairing over disparities: an empirical analysis of the relationship between willingness-to-pay and willingness-to-accept. Environ Resour Econ (Dordr). 1999;13(2):219-34.
López MV, Rivero E, Serra C, Campo M, Raurich M, Bonfill X. Health survey in health care professionals in Barcelona. Arch Prev Riesgos Laborales. 1998;1(2):55-62.