000 00275nam a2200121Ia 4500
001 5314
008 190520s9999 xx 000 0 und d
020 _a9789584538581
100 1 _aNohra León ..[et al. ]
245 1 0 _aRetos sociales grado 9
260 _bNorma
942 _cCA
999 _c17756
_d17756