6th IASME/WSEAS International Conference on Energy and Environment (EE'11), Cambridge, UK, February 23-25, 2011, ISSN 1792-8230, ISBN 978-960-474-274-5, pp. 261-265
6-th IASME/WSEAS International Conference on Energy & Environment (EE'11), Cambridge, UK, February 23-25, 2011,ISSN 1792-8230,ISBN 978-960-474-274-5, pp. 266-271