1.
Truth, Deduction, and Computation: Logic and Semantics for Computer Science - Ruth E. Davis ...
by Davis, Ruth E.
ISBN: 9780716782018
2.
Ysgol Gynradd Dolforwyn, Abermiwl, Trefaldwyn, Powys, SY15 6ND: Arolygiad dan Adran 9 o Dded...
by E. Ruth Davies
ISBN: 9780750413633