APA (7th ed.) Citation

Pius papa, I. (1870). Preussen betreffende Schriften.

Chicago Style (17th ed.) Citation

Pius papa, II. Preussen Betreffende Schriften. 1870.

MLA (9th ed.) Citation

Pius papa, II. Preussen Betreffende Schriften. 1870.

Warning: These citations may not always be 100% accurate.