Quadratic Voting by Steven P. Lalley and E. Glen Weyl. This is the original paper that proposed QV.
Democracy Squared by Eric A. Posner and E. Glen Weyl. A detailed argument for QV with real money in democratic politics.
The Robustness of Quadratic Voting by E. Glen Weyl. A mathematical analysis, based on approximation arguments, of the robustness of QV to collusion, imperfect rationality, various voter motivations and richer information structures.
One Man, One Vote Bid by Jacob Goeree and Jingjing Zhang. The first laboratory experimental study of QV, indicating it dramatically out performs one-person-one-vote along many dimensions.
Quadratic Voting in the Wild by David Quarfoot, Douglas von Kohorn, Kevin Slavin, Rory Sutherland, David Goldstein and Ellen Konar. The first large-scale field test of QV for political polling, indicating that it elicits intensity of preference more accurately than the Likert scale.
Quadratic Election Law by Eric A. Posner and Nicholas Stephanopoulos. A detailed analysis of the relationship of QV to American election and constitutional law.
Towards Secure Quadratic Voting by Sunoo Park and Ronald L. Rivest. Cryptographic protocols for implementing in-person and online QV securely and verifiably.