Gorny, N. Northern Song Dynasty Cash Variety Guide 2016. (Morrisville, NC, 2016).
This
catalog is the key to studying, understanding, and collecting Northern
Song dynasty Chinese cash. It enables the collector to reference and
build a collection intelligently. It can lead to new discoveries. It
encourages numismatic interest in East Asian history and coinage. If one
has any quantity of Song dynasty coins, one will very likely be able to
find them all in this catalog and own a very impressive, documented
collection.