Lennon RP, Miller EL, Snyder B, Van Scoy LJ. Self-reported influenza and influenza-like symptoms in U.S. adults age 18-64 between September 1, 2019 and April 15, 2020. J Clin VIrol. 2021 Jan;134:104709. doi: 10.1016/j.jcv.2020.104709
Whittington D, Sur D, Cook J, Chatterjee S, Maskery B, Lahiri M, Poulos C, Boral S, Nyamete A, Deen J, Ochiai L, Bhattacharya SK. Rethinking cholera and typhoid vaccination policies for the poor: private demand in Kolkata, India. World Dev. 2009 Feb 1;37(2):399-409.