Peter F. Drucker...[et al.] Peter F. Drucker...[et al. Peter Turner...[et al.] Peter Turner...[et al. Roger H. Seifter...[et al.] Benedict Walker...[et al.] Bruce W. Frier... [et al.] Patricia Junker...[et al.] Roger H. Seifter...[et al. by Beryl Packer...[et al.]