Start with high-confidence shinto books, then narrow by subgenre or adjacent topics.
Shinto
Helen Hardacre
A Year in the Life of a Shinto Shrine
John K. Nelson
A Study of Shinto
Genchi Katu
A New History of Shinto
John Breen, Mark Teeuwen
The Essence of Shinto
Motohisa Yamakage
Japanese Culture
Roger J. Davies
