1.  Dai Nihon chimei jisho,  大日本地名辭書 by Yoshida Tōgo, 8 vols  (revised edition, 1970)  (Most important place name encyclopedia, giving information on the importance of the place in history and literature.  Kanji index of some difficult readings.

2.   Nihon chimei daijiten,  日本地名大事典 by Asakura Shoten (1967-68) A seven volume work arranged by region.  Each volume with a kana index.  For identification of contemporary place names.

3.   Nihon chimei daijiten,  日本地名大事典 by Sawada Hisae (1937-38)  Six volumes. Arranged alphabetically, for place names in modern times to 1938.

4.   Konsaisu chimei jiten (Nihon-hen),  コンサイス地名辞典 (日本編) by Sanseidō   (1975) Very convenient for its character stroke index.