Obourn, E. S. (1958). Activities in science: Workbook to accompany science in everyday life (2nd edition.). D. Van Nostrand Co.
Lua i Stíl Chicago (17ú heag.)Obourn, Ellsworth S. Activities in Science: Workbook to Accompany Science in Everyday Life. 2nd edition. Princeton, New Jersey: D. Van Nostrand Co, 1958.
Lua MLA (9ú heag.)Obourn, Ellsworth S. Activities in Science: Workbook to Accompany Science in Everyday Life. 2nd edition. D. Van Nostrand Co, 1958.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.