Carnival Glass Books
The below books, in my opinion, provide the best information about the history, patterns, and colors produced by the major makers of Carnival Glass. While most are out of print, they can often be found on eBay or at amazon.com as used books.
Fenton Glass, The First Twenty-five Years

Published 1978

by William Heacock

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Also: The Second Twenty-five Years, The Third Twenty-five Years, The 1980s Decade
Harry Northwood, The Wheeling Years, 1901-1925

Published 2001

by William Heacock, James Measell, Berry Wiggins

Antique Publications
Northwood Carnival Glass, 1908-1925

Published 2001

by Carl O. Burns

Collector Books
Dugan/Diamond, The Story of Indiana, Pennsylvania, Glass

Published 1993

by William Heacock, James Measell, Berry Wiggins

Antique Publications
Dugan & Diamond Carnival Glass, 1909-1931

Published 1999

by Carl O. Burns

Collector Books
Imperial Carnival Glass

Published 1996

by Carl O. Burns

Collector Books
Millersburg Glass

Published 1995

by Marie McGee

Antique Publications
Carnival Glass, The Magic and Mystery

Published 1998

by Glen and Stephen Thistlewood

Schiffer Publishing Ltd
A Century of Carnival Glass

Published 2001

by Glen and Stephen Thistlewood

Schiffer Publishing Ltd
The Art of Carnival Glass

Published 2004

by Glen and Stephen Thistlewood

Schiffer Publishing Ltd