Arg. Saesneg gwreiddiol = Original English ed.: Harcourt Brace Jovanovich, 1991.
Cyhoeddwyd dan nawdd Cynllun Adnoddau Cyd-bwyllgor Addysg Cymru = Publication sponsored by Welsh Joint Education Committee Cynllun Adnoddau.
Mathemateg HBJ : llyfr gweithgareddau blwyddyn 4: neidio/mwy a llai. ISBN 0003005488. Published by Collins Educational in 1994. Publication and catalogue information, links to buy online and reader comments.