PHP研究所 (PHPkenkyuujo/kenkyuusho) · 文藝春秋 (bungeishunjuu)
| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Kodai Nihon Tanjō No Nazo: Yamato Chōtei Kara Tōitsu Kokka E | 978-4-569-66579-5 (4-569-66579-9) | 2006 |
| Myoji no Nihonjin | 978-4-16-660011-3 (4-16-660011-7) | 2001 |