Collins, Ian; Rowley, Michael; Davey, William B.; Emms, Frances; Marwood, Rosemarie; Patel, Shil; Patel, Smita; Fletcher, Alan; Ragan, Ian C.; Leeson, Paul D.; Scott, Ann L.; Broten, Theodore Bioorganic and Medicinal Chemistry, 1998 , vol. 6, # 6 p. 743 - 753