Papua New Guinea. Department of Education. (1987). Secondary school mathematics 9A: Teachers' guide. Department of Education.
Citazione stile Chigago Style (17a edizione)Papua New Guinea. Department of Education. Secondary School Mathematics 9A: Teachers' Guide. Port Moresby: Department of Education, 1987.
Citatione MLA (9a ed.)Papua New Guinea. Department of Education. Secondary School Mathematics 9A: Teachers' Guide. Department of Education, 1987.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.