Ecoleg /
Rowlands, David,1950-
Owen, Einir.
Welsh Joint Education Committee.Cynllun Adnoddau.
Caerdydd : Qualitex mewn cydweithrediad â Longman Group,
1994.
Arg. Saesneg gwreiddiol = Original English ed: Harlow: Longman Group, 1992
Testun tu mewn i'r cloriau = Text on inside covers
Teitl clawr = Cover title
Cyhoeddwyd dan nawdd Cynllun Adnoddau Cyd-bwyllgor Addysg Cymru = Published under the auspices of the Welsh Joint Education Committee Resource Project
Ecology