Aperiodic Crystals Siegbert Schmid, Ray L. Withers, Ron Lifshitz E-Book (pdf)

Essentials of Chemical Education Hans-Dieter Barke, Günther Harsch, Siegbert Schmid E-Book (pdf)

The Chemistry of Sulphur, Selenium, Tellurium and Polonium M. Schmidt, W. Siebert, K. W. Bagnall E-Book (pdf)