Charles, R. I. (1991). Problem-solving experiences in general mathematics: Teacher sourcebook. Addison-Wesley.
Citazione stile Chigago Style (17a edizione)Charles, Randall I. Problem-solving Experiences in General Mathematics: Teacher Sourcebook. Menlo Park: Addison-Wesley, 1991.
Citatione MLA (9a ed.)Charles, Randall I. Problem-solving Experiences in General Mathematics: Teacher Sourcebook. Addison-Wesley, 1991.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.