edit by William K.Purves...[et al edit by William K.Purves...[et al] edit by William S.Davis...[et al edit by William G.Nickels...[et al edit by William P.Finley...[et al edit by William S.Davis...[et al] edit by William G.Nickels...[et al] edit by William F.Sharpe...(et al) edit by William P.Finley...[et al] edit by Willam G.Nickels...[et al