This author has not been identified. Look up 'H. Tran' in GoogleThis author has not been identified. It may be one of the following persons: Look up 'Laurence Duchien' in GoogleThis author has not been identified. Look up 'Philippe Bedu' in GoogleThis author has not been identified. Look up 'H. Nguyen' in GoogleThis author has not been identified. Look up 'Jean Perrin' in Google