This is a reprint, with no new additions indicated, of a 1993 work which presents 19 foundational papers on fractal geometry published before 1967. Twelve of the papers are here translated into English for the first time. The notes, commentary, bibliographies, and index have made this a useful resource that is worth reprinting in this paperback edition. The review of the first version (1993; Zbl 0795.28007) includes an indication of the contents.