Effective lower bounds on large fundamental units of real quadratic fields
\textit{Y. Yamamoto} [ibid. 8, 261--270 (1971; Zbl 0243.12001)], gave classes of large fundamental units for real quadratic fields. The author uses again some hypotheses about ideals being principal to imply some effective lower bounds on fundamental units. Though Gauss' conjecture that infinitely many real quadratic fields have class number one is still open, his results are very interesting.
scientific article; zbMATH DE number 3939447