@Article{ VALVERDE_CASTRO:1-17,

author = { ANA GABRIELA VALVERDE SOTO and ENCARNACION CASTRO MARTINEZ } ,

title = { Prospective Elementary School Teachers Proportional Reasoning },

journal = { PNA },

year = { 2012 },

volume = { 7 },

issn = { 1886-1350 },

pages = { 1-17 },

doi = { https://dl.dropbox.com/u/92002238/paginapna/Numeros2/pdf/Valverde2012Prospective.pdf },

}