Crossover Plus 2 Teacher's Book
Autor:Sánchez de la Barquera, Angélica; Gardner Wilson, John WilliamsonCrossover Plus 1 Teacher's Book
Autor:Milne Thompson, Kim; Sánchez de la Barquera, AngélicaTeacher´s Guide Crossover Plus 2
Autor:Sánchez de la Barquera, Angélica; Gardner Wilson, John Williamson