@Article{ MOLINA_Ambrose-:61-80,

author = { MARTA MOLINA and Rebecca Ambrose- } ,

title = { FROM AN OPERATIONAL TO A RELATIONAL CONCEPTION OF THE EQUAL SIGN. THIRDS GRADERS¿ DEVELOPING ALGEBRAIC THINKING. },

journal = { Focus on learning problems in mathematics },

year = { 2008 },

volume = { 30 },

pages = { 61-80 },

}