Wardman M, Chintakayala PK, de Jong G. Values of travel time in Europe: review and meta-analysis. Transp Res Part A Policy Pract. 2016 Dec;94:93-111. doi: 10.1016/j.tra.2016.08.019
Bogerd HP, Wiegand HL, Yang J, Cullen BR. Mutational definition of functional domains within the Rev homolog encoded by human endogenous retrovirus K. J Virol. 2000 Oct;74(20):9353-61.