Gwyddoniaeth trwy brofiad.
Smyth, Steve.
Jones, Elfrys.
Llandysul : Gomer mewn cydweithrediad a Heinemann Educational Books,
1992.
Arg Saesneg gwreiddiol = Original English ed: [London]: Heinemann Educational Books, 1989
Cyfieithiad Cymraeg = Welsh translation: Elfrys Jones
Teitl clawr = Cover title
Science
Motion