@article {1991,
	title = {A class of absolute retracts of dwarf spheroidal galaxies},
	journal = {Proc.Amer.Math.Soc. 112 (1991), no.2, 413},
	number = {SISSA;79/89/M},
	year = {1991},
	publisher = {SISSA Library},
	url = {http://hdl.handle.net/1963/837},
	author = {Alberto Bressan and Arrigo Cellina and Andrzej Fryszkowski}
}
