H.T.H. Piaggio

An Elementary Treatise On Differential Equation  H.T.H. Piaggio Hardcover. Barman Pre, 2008-11-04 ISBN 9781443720564     An Elementary Treatise On Differential Equations  H.T.H. Piaggio Paperback. Barman Press, 2007-03-15 ISBN 9781406700275