Llygredd
By: awdur: David Rowlands ; addasiad Cymraeg: Thomas Davies.
Contributors: Davies, Thomas.
Series: Gwyddoniaeth ar waith
Publisher: Qualitex mewn cydweithrediad â Longman
Published: 1991
Place of publication: Caerdydd
Language: wel
Number of pages: 32
Subjects: Pollution -- Study and teaching (Secondary)
Work titles: Pollution.
Notes: Arg Saesneg gwreiddiol = Original English ed: Addison-Wesley, 1979.

Addasiad Cymraeg o = Welsh adaptation of: Science at work: Pollution.