 letter editor assess inform servic mai rais question time govern polici retriev consid? these produc sdc german dr somerfield's paper 'comput-base inform servic' aslib proceed 20 12 542-50 1968 osti's work field the sdc make comparison effici publish index sourc scientif rigor check comparison case studi subject 'comput relat mass spectrometri' thi extens literatur search prepar combin collat search twelv world's major index chemistri spectroscopi includ search sdc's data bank file nearli uniqu refer 'comput relat mass spectrometri' check individu relev go origin paper expert opinion 