@article {,
	title = {Verifying a P system generating squares},
	journal = {Romanian Journal of Information Science and Technology},
	volume = {5},
	year = {2002},
	pages = {181-191},
	publisher = {EDITURA ACADEMIEI ROM{\^A}NE},
	address = {Bucure{\c s}ti, Rom{\^a}nia},
	keywords = {Formal Verification, Membrane computing, Natural computing},
	issn = {1453-8245},
	url = {http://www.cs.us.es/~marper/investigacion/resumen-cuadrados.pdf},
	author = {Mario J. P{\'e}rez-Jim{\'e}nez and Fernando Sancho-Caparrini}
}
