@conference {DBLP:conf/dasfaa/ZhaoY07,
	title = {{M}ining {C}losed {F}requent {F}ree {T}rees in {G}raph {D}atabases},
	booktitle = {DASFAA},
	year = {2007},
	pages = {91-102},
	author = {Peixiang Zhao and Yu, Jeffrey Xu}
}
