Obourn, E. S. (1958). Activities in science: Workbook to accompany science in everyday life (2nd edition.). D. Van Nostrand Co.
Citazione stile Chigago Style (17a edizione)Obourn, Ellsworth S. Activities in Science: Workbook to Accompany Science in Everyday Life. 2nd edition. Princeton, New Jersey: D. Van Nostrand Co, 1958.
Citatione MLA (9a ed.)Obourn, Ellsworth S. Activities in Science: Workbook to Accompany Science in Everyday Life. 2nd edition. D. Van Nostrand Co, 1958.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.