@article{ Ionescu_Popescu_PRL_2015,
	author = {Radu Tudor Ionescu and Marius Popescu},
	title = "{PQ kernel: a rank correlation kernel for visual word histograms}",
	year = {2015},
	journal = {Pattern Recognition Letters},
	month = {September},
	publisher = {Elsevier},
	volume = {55},
	pages = {51--57},
}