APA (7th ed.) Citation

Autograph letter of Albert Einstein to Harr Muands on the Hamiltonian function, 18 Dec. [1929?].

Chicago Style (17th ed.) Citation

Autograph Letter of Albert Einstein to Harr Muands on the Hamiltonian Function, 18 Dec. [1929?].

MLA (9th ed.) Citation

Autograph Letter of Albert Einstein to Harr Muands on the Hamiltonian Function, 18 Dec. [1929?].

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