{{ Kilde bok | utgivelsesår = 1956 | tittel = International guide to sources of technical information | utgivelsessted = Paris | forlag = European Productivity Agency of the Organisation for European Economic Co-operation | side = }}{{ Kjelde bok | utgjeve år = 1956 | tittel = International guide to sources of technical information | stad = Paris | forlag = European Productivity Agency of the Organisation for European Economic Co-operation | side = }}