Two boxed bottles of De Trey's thymozin, by De Trey Bros., Zurich, Switzerland, 1925-1930 Two boxed bottles of De Trey's thymozin Dentistry 1925-1930
Boxed bottles of De Trey's thymozin, by De Trey Bros., Zurich, Switzerland, 1930-1960 Boxed bottles of De Trey's thymozin Dentistry 1930-1960
