Cita APA (7a ed.)

Janssen, M. (1896). Four day's observations at the summit of Mont Blanc. Government Printing Office.

Cita Chicago Style (17a ed.)

Janssen, M.J. Four Day's Observations at the Summit of Mont Blanc. Washington: Government Printing Office, 1896.

Cita MLA (9a ed.)

Janssen, M.J. Four Day's Observations at the Summit of Mont Blanc. Government Printing Office, 1896.