Tables of imaginary quadratic fields with small class numbers
A single-page compilation listing the imaginary quadratic fields of class number h for h = 1 through 7 and every odd h up to 23 — 629 fields in all — transcribed from the determinations of Arno, Arno-Robinson-Wheeler, Wagner, and Ribenboim. Depending on the section, fields are given by field discriminant or by squarefree d, as flagged on the page.
This data is now subsumed by the LMFDB, whose number field database at https://www.lmfdb.org/NumberField/ contains all imaginary quadratic fields of class number up to 100 (following Watkins’s determination).