 gener us machin-readabl data base thi chapter continu coverag gener machin-readabl data base inaugur volum 9 william 178 it updat consist 1974 materi prepar gener william's initi compil the definit data base boundari applic volum 9 continu year a data base consid organ collect machin-readabl record bibliograph document-relat data the data base consid storag retriev storag retriev data base gener the choic constraint preclud coverag area first data base concern numer nonbibliograph chemic structur milen al 112 exclud thu chemic abstract servic ca registri number data element common bibliograph data base paper ca progress build registri system 39 exclud similarli textual bibliograph materi includ system consult inc report 156 navi retriev concern miniatur hardwar shipboard environ consid scope chapter final data base gener public phototypeset consid product oper 