The voting experience and beliefs about ballot secrecy. Dowling CM, Doherty D, Hill SJ, Gerber AS, Huber GA.PLoS One. 2019 Jan 7;14(1):e0209765 

Evaluating ballot initiative support for legalised marijuana: The case of Washington. Collingwood L, O'Brien BG, Dreier S.Int J Drug Policy. 2018 Jun;56:6-20.  

Expansion by Ballot Initiative: Challenges and Future Directions in Health Policy. Singer PM, Nelson DB.J Gen Intern Med. 2019 Sep;34(9):1913-1915.