APA

Guggenberger A., . (1899). A general history of the Christian era. : Herder.

Chicago

Guggenberger A, . 1899. A general history of the Christian era. : Herder.

Harvard

Guggenberger A., . (1899). A general history of the Christian era. : Herder.

MLA

Guggenberger A, . A general history of the Christian era. : Herder. 1899.