@article {kocia2015directed,
	title = {Directed HK propagator},
	journal = {The Journal of Chemical Physics},
	volume = {143},
	year = {2015},
	pages = {124102},
	publisher = {AIP Publishing},
	url = {http://scitation.aip.org/content/aip/journal/jcp/143/12/10.1063/1.4931406},
	author = {Kocia, Lucas and Heller, EricJ.}
}
