P. Felzenszwalb, R. Girshick, D. McAllester, D. Ramanan, Object Detection with Discriminatively Trained Part-Based Models, IEEE Pattern Analysis and Machine Intelligence (PAMI). Sept 2010.
And optionally:
Tomasz Malisiewicz, Abhinav Gupta, Alexei A. Efros, Ensemble of Exemplar-SVMs for Object Detection and Beyond, In ICCV 2011.
B. Hariharan, J. Malik, D. Ramanan. Discriminative Decorrelation for Clustering and Classification, ECCV 2012.