 us machin-readabl data base thi annual review chapter entitl us machin- readabl data base therefor coverag provid on-year period a chapter gechman 79 machin-readabl bibliograph data base includ literatur 1969 1971 a chapter housman 100 cover data base select dissemin sdi chapter parkin kennedi 153 review secondari servic thi chapter cover 1973 literatur data base well earlier data base paper treat prior chapter for purpos chapter data base consid organ set machin-readabl record bibliograph document-relat data 