Parry-Williams, T.H. Pensynnu [ysgrifau]

Gwasg Gomer, 1966. 90t., clawr caled, siaced lwch. Copi glan iawn.

£5.00, cost cludiant yn ychwanegol, Rhif Cat. 537.

A dad from israel has designed a system where his children need to work out on an exercise bike, if they want to use a computer