@article {cuervo2005path,
	title = {Path integral ground state with a fourth-order propagator: Application to condensed helium},
	journal = {The Journal of chemical physics},
	volume = {122},
	number = {11},
	year = {2005},
	pages = {114504},
	publisher = {American Institute of Physics},
	author = {Cuervo, Javier E and Roy, Pierre-Nicholas and Boninsegni, Massimo}
}
