Taenlenni ar gyfer mathemateg a thechnoleg gwybodaeth /
Rothery, Andrew.
Kirkman, Dafydd.
University College of Wales (Aberystwyth, Wales).Centre for Educational Studies.
Aberystwyth : Canolfan Astudiaethau Addysg,
1994.
Arg. Saesneg gwreiddiol = Original English ed: London: John Murray, 1991
Mathematics
Electronic spreadsheets.