Vase in ice-glass technique (shortly kept in cold water and immediately reheated and blown), executed by Joh. Loetz Witwe, Bohemia 1900-'02
Lötz, Böhmishes Glas 1880-1940, Band 1, "Werkmonographie" by Helmut Ricke, published by Prestel / no. 156 page 159 & no.170 page 167