Why is New Hampshire the first primary in the nation?” Elaine Kamarck, Brookings Institution, 2016

The can't-miss 2019 calendar for 2020 candidates,” Lauren Dezenski, CNN, 2018

U.S. Election Statistics: A Resource Guide,” compiled by the Library of Congress

National Association of Secretaries of State election information

AP VoteCast, a new way to track how people voted

National Election Pool, the network consortium that conducts exit polls

“The 2017 elections boosted the confidence of exit pollsters – and their future competitors,” The Washington Post