Федоров Е.С. Следы проявления триклинной сингонии в ортоклазе // Записки Горного института. 1908. Т. 1 № 5. С. 392-394.
Fedorov Y.S. // Journal of Mining Institute. 1908. Vol. 1 № 5. p. 392-394.
Among the remarkable examples of potassium feldspar in the Museum of the Mining Institute there is a very large adularia quadruple from St. Gotthard (Fibia), reproduced in Fig. 1 of the attached table (up to two decimeters in length).