essays by Peter Walker...[et al.] essays by Peter Walker...[et al. essays by Dieter Buchhart...[et al.] essays by Jed Morse...[et al.] essays by Kay Heymer...[et al.] essays by Dieter Buchhart...[et al. essays by Cynthia Becker...[et al. essays by Jed Morse...[et al. essays by Kay Heymer...[et al. essays by Keith Eggener...[et al.