Greibach, S. A. An infinite hierarchy of context-free languages. (English) Zbl 0182.02002 J. Assoc. Comput. Mach. 16, 91-106 (1969). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 52 Documents Keywords:recursion theory, constructive mathematics PDFBibTeX XMLCite \textit{S. A. Greibach}, J. Assoc. Comput. Mach. 16, 91--106 (1969; Zbl 0182.02002) Full Text: DOI