@article {,
	title = {P systems on graphs of restricted forms},
	journal = {Publicationes Mathematicae Debrecen},
	volume = {60},
	year = {2002},
	pages = {635-660},
	address = {Debrecen, Hungr{\'\i}a},
	issn = {0033-3883},
	author = {Gheorghe Paun and Y. Sakakibara and Takashi Yokomori}
}
