A comprehensive description is given of a retrieval system which can be applied to the personal library of an individual scientist, to the general library of a laboratory or research unit, and to bibliographies of abstracts. The methods used are described in terms of their application to the field of Human Factors, but they are relevant to similar information storage and retrieval problem in any field. Primary features of the system are the serial assignment of accession numbers, an author card file, an accession card file, search using ‘feature’ cards (‘peek-a-boo’), a specially designed desk for storing, punching, and searching the feature cards, and the adoption of the Tufts Topical Outline as the index language. Full operating instructions are given in an appendix.