@article {Heun/2008,
	title = {{Analysis of a Modification of Gusfield{\textquoteright}s Recursive Algorithm for Reconstructing Ultrametric Trees}},
	journal = {Information Processing Letters},
	volume = {108},
	number = {4},
	year = {2008},
	pages = {222-225},
	keywords = {heun-group},
	doi = {10.1016/j.ipl.2008.05.008},
	author = {Volker Heun}
}