O., B., G., Julius, S.(1979).Elementary school science and how to teach it / Glenn O. Blough, Julius Schwartz (Ed.ke-6).:Holt, Rinehart and Winston.
Gaya MLA
Blough, Glenn, O.., Schwartz, Julius."Elementary school science and how to teach it / Glenn O. Blough, Julius Schwartz".Ed.ke-6:Holt, Rinehart and Winston,1979.Skripsi.