1. Conjectures and refutations: The growth of scientific knowledge;Popper,1969
2. The structure of scientific revolutions;Kuhn,1970
3. Factors determining the performance of indexing systems;Cleverdon,1966
4. Factors determining the performance of indexing systems;Cleverdon,1966
5. Search procedures in the library analysed from the cognitive point of view;Ingwersen;Journal of Documentation,1982