This author has not been identified. Look up 'A. Dougan' in GoogleThis author has not been identified. Look up 'D. Gavel' in GoogleThis author has not been identified. Look up 'D. Gustaveson' in GoogleThis author has not been identified. Look up 'M. Holliday' in GoogleIdentified as Ralph E. Johnson This author has not been identified. Look up 'B. Kettering' in GoogleThis author has not been identified. Look up 'H. Wilhelmsen' in Google