Wayne Richter. Extensions of the constructive ordinals. The journal of symbolic logic, vol. 30 (1965), pp. 193–211. - Wayne Richter. Constructive transfinite number classes. Bulletin of the American Mathematical Society, vol. 73 (1967), pp. 261–265. - Wayne Richter. Constructively accessible ordinal numbers. The journal of symbolic logic, vol. 33 (1968), pp. 43–55.
Gustav B. Hensel · Journal of Symbolic Logic · 1971
Wayne Richter. Extensions of the constructive ordinals. The journal of symbolic logic, vol. 30 (1965), pp. 193–211. - Wayne Richter. Constructive transfinite number classes. Bulletin of the American Mathematical Society, vol. 73 (1967), pp. 261–265. - Wayne Richter. Constructively accessible ordinal numbers. The journal of symbolic logic, vol. 33 (1968), pp. 43–55. - Volume 36 Issue 2