Sut mae'n gweithio
By: Roland Berry ; addaswyd i'r Gymraeg gan Iwan Bryn Williams.
Contributors: Williams, Iwan Bryn.
Publisher: Chrsitopher Davies
Published: 1978
Place of publication: Abertawe
Language: wel
Number of pages: 64
Subjects: Technology -- Juvenile literature.
Work titles: Berry's book of how it works.
Notes: Translation of, 'Berry's book of how it works'. London , A. and C. Black, 1976.