Johnson, Fred (Frederick A.), authorInstitute of Philosophy and Sociology, Polish Academy of Sceinces, publisher2007-01-032007-01-031977Johnson, Frederick A., A Natural Deduction Relevance Logic, Bulletin of the Section of Logic 6, no. 4 (1977): 164-170.http://hdl.handle.net/10217/85940born digitalarticleseng©1977 Polish Academy of Sciences, Institute of Philosophy and Sociology.Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.logiclanguageNDRText