[745] Escombe 1896.

[746] Wisselingh 1898.

[747] Wester 1909.

[748] Berzelius 1813.

[749] Guérin-Varry 1834.

[750] Mulder 1838.

[751] Berg 1873.

[752] Beilstein ex Errera 1882, p. 16 (note).

[753] Escombe 1896.

[754] Wiesner 1900.