1. “Chemical composition and deterioration of glass excavated in the 15th-16th century fishermen town of Raversijde (Belgium)”. Schalm O, Caluwé D, Wouters H, Janssens K, Verhaeghe F, Pieters M, Spectrochimica acta: part A: molecular and biomolecular spectroscopy 59, 1647 (2004).   http://doi.org/10.1016/J.SAB.2004.07.012