Boehringer, Erich. Die Münzen von Syrakus. (Berlin and Leipzig, 1929). 297 pp., 32 plates. Forni reprint.
The definitive die study for the period 510-415 BC.
The coins of Syracuse
PDF available at Academia.edu (separate files for text, catalog, and plates).
Also see by the following by Christof Boehringer:
Boehringer Chronologie
Boehringer Finanzpolitik
Boehringer Frühen
Boehringer Geschichte
Boehringer Herbita
Boehringer Himera
Boehringer Kataneische
Boehringer Leontini
Boehringer Münzprägungen
Cosimo
Ognina