1995 Y. Xu & E. Braune “A guideline for groundwater protection for the community water supply and sanitation programme”, Published by the Department of Water Affairs and Forestry, RSA,
ISBN: 0-621-16787-8.

2003 Y. Xu & H E. Beekman (Eds) “Groundwater recharge estimation in Southern Africa”, UNESCO IHP Series No. 64, published by UNESCO Paris. ISNB 92-9220-000-3.

2006 Y Xu & B Usher (Eds) “Groundwater Pollution in Africa”. Published by Taylor & Francis / Balkema, ISBN 10: 0-415-41167-X. UK

2010 Y Xu & E Braune (Eds) “Sustainable groundwater resources in Africa: water supply and sanitation environment”, published by Taylor & Francis / Balkema, ISBN Hardback: 978 0 41587603 2, ISBN e-Back: 978 0 203 85945 2, The Netherlands and UK