Patterson, G., G. Van Horn, S. Belongie, P. Perona, and J. Hays. “Tropel: Crowdsourcing Detectors With Minimal Training”. Proceedings of the AAAI Conference on Human Computation and Crowdsourcing, vol. 3, no. 1, Sept. 2015, pp. 150-9, doi:10.1609/hcomp.v3i1.13224.