SEELER, M. 1969. The Art of Enamelling: How to Shape Precious Metal and Decorate it with cloisonné, champlevé, plique-à -Jour, mercury gilding and other fine technics, Pennsylvania State University, Van Nostrand Reinhold Company.
SPEEL, E. 1998. Dictionary of Enamelling: History and techniques, England, Ashgate Publishing Limited.