APA (7th ed.) Citation

Bohr, N., & Nielsen, J. R. (1977). The periodic system (1920-1923). North-Holland Pub. Co..

Chicago Style (17th ed.) Citation

Bohr, Niels, and J. Rud Nielsen. The Periodic System (1920-1923). Amsterdam: North-Holland Pub. Co., 1977.

MLA (9th ed.) Citation

Bohr, Niels, and J. Rud Nielsen. The Periodic System (1920-1923). North-Holland Pub. Co., 1977.