PATENT

3668. ----- [STUDIEN-UND VERWERTUNGS-G. M. B. H.]  [Gas Purification.]  Netherlands Patent 42,296, no date. Schmidt, J., Das Kohlenoxyd, Akad. Verlagsgesell., Leipzig, 1950, p. 168.

See United States Patent 2,110,140 (abs. 2811).