“Inferring Ground Truth from Subjective Labelling of Venus Images” Padhraic Smyth, Usama Fayyad, Michael Burl, Pietro Perona, Pierre Baldi. NIPS 1994, Advances in Neural Information Processing 7, G. Tesauro, D. S. Touretzky, and T.K. Lenn (eds.), pp. 1085-1092, MIT Press, Denver, Colorado, July (1995).