Gaya APA

Billstein, R., W, I, L, S, I, L, J. (2010). A problem solving approach to mathematics for elementary school teachers . Boston: .

Gaya MLA

Billstein, Rick., W, I., Libeskind,, Shlomo, II., Lott,, Johnny. "A problem solving approach to mathematics for elementary school teachers". Boston: , 2010. .