Butler AM, Layton JB, Krueger WS, Kshirsager AV, McGrath LJ. Assessing residual bias in estimating influenza vaccine effectiveness: comparison of high-dose versus standard-dose vaccines. Med Care. 2019 Jan;57(1):73-8. doi: 10.1097/MLR.0000000000001018
Yang J, Bogerd HP, Peng S, Wiegand H, Truant R, Cullen BR. An ancient family of human endogenous retroviruses encodes a functional homolog of the HIV-1 Rev protein. Proc Natl Acad Sci U S A. 1999 Nov 9;96(23):13404-8.