Suppression of lead leaching from overglaze decoration of porcelain tableware by the sol-gel silica-coating - HORIUCHI, T; SUGIYAMA, T; MIZUNO, K; OSAKI, T; SUZUKI, K; TOMURA, S; MORI, T (Nihon Seramikkusu Kyōkai gakujutsu ronbunshi, 1996)