Tham khảo Thụ_thừa

  1. ↑ Perstein, Millard H. (tháng 6 năm 1962), “Algorithm 93: General Order Arithmetic”, Communications of the ACM 5 (6): 344, doi:10.1145/367766.368160 .
  2. ↑ Goodstein, R. L. (1947), “Transfinite ordinals in recursive number theory”, The Journal of Symbolic Logic 12 (4): 123–129, JSTOR 2266486, MR 0022537, doi:10.2307/2266486 .
  3. ↑ Knuth, D. E. (1976), “Mathematics and computer science: Coping with finiteness”, Science 194 (4271): 1235–1242, PMID 17797067, doi:10.1126/science.194.4271.1235 .
  4. ↑ Blakley, G. R.; Borosh, I. (1979), “Knuth's iterated powers”, Advances in Mathematics 34 (2): 109–136, MR 549780, doi:10.1016/0001-8708(79)90052-5  Đã bỏ qua tham số không rõ |doi-access= (trợ giúp).
  5. ↑ Conway, John Horton; Guy, Richard (1996), The Book of Numbers, Springer, tr. 61, ISBN 9780387979939 .
  6. ↑ http://www.tetration.org/Tetration/index.html
  7. ↑ Nambiar, K. K. (1995), “Ackermann functions and transfinite ordinals”, Applied Mathematics Letters 8 (6): 51–53, MR 1368037, doi:10.1016/0893-9659(95)00084-4  Đã bỏ qua tham số không rõ |doi-access= (trợ giúp).