@article {feng2005universal,
	title = {The universal validity of the possible triangle constraint for affected sib pairs},
	journal = {Canadian Journal of Statistics},
	volume = {33},
	number = {2},
	year = {2005},
	pages = {297{\textendash}310},
	publisher = {Wiley Online Library},
	author = {Feng, Zeny Z and Chen, Jiahua and Thompson, Mary E}
}
