List of reference books I like to use, I own most of these unless the link is to a E-text.
Mold glass
Roman Mold Blown Glass the First Through Sixth Centuries by E. M. Stern and the Toledo Museum of Glass
Ennion : master of Roman glass by C S Lightfoot; Zrinka Buljević; Yael Israeli; Karol Wight; M T Wypysk
Glass
Beginning Glassblowing By Edward T Schmid
A Glass Blowers Companion By Dudley Giberson, Jr
Glass Notes: A reference for the glass artist By Halem
Chains
Classical Loop-in-Loop Chains and their Derivatives by Jean Reist Stark; Josephine Reist Smith