Escape DOI: https://doi.org/10.3776/ncl.v18i1.4571 Downloads PDF Published 1959-01-01 Issue Vol 18, No 1 (1959) Section Research & Librarianship License Articles published 2023 and later: (C) The Authors, released under CC-BY license Articles published 2022 and earlier: Released under a CC-BY-NC license
