by Robert M. Johnston ... [et al.]. by Robert U. Ayres ... [et al.]. by Robert Cook ... [et al.] Alan R. Johnston ... [et al.] by Roberto Serra ... [et al.]. by Roger S. Haydock ... [et al.] by Robert C. Pooley ... by Robert A. Hanneman. by Robert J. Boswell. by Robbert B. Reich; John D. Donahue.