@article {6704,
	title = {An empirical evaluation of the use of the ontogenetic polarization criterion in phylogenetic inference},
	journal = {Systematic Zoology},
	volume = {37},
	year = {1988},
	note = {PDF},
	pages = {106- 141},
	keywords = {heterochrony, phylogenetics},
	author = {Krauss, F.}
}
