Llywodraeth Cynulliad Cymru : menter nofio am ddim : adroddiad crynodeb data : data hyd at fis Medi 2010 = Welsh Assembly Government : free swimming initiative : data summary report : data up to Septe. ISBN 187155313X. Published by Uned Ddata Llywodraeth Leol - Cymru in 2011. Publication and catalogue information, links to buy online and reader comments.