Mathematical problem - autograph manuscript, likely by Ruskin.
MLA
Ruskin, John, 1819-1900. Mathematical problem - autograph manuscript, likely by Ruskin.. Box 31. undated. https://collections.library.yale.edu/catalog/2020260.
APA, 6th edition
Ruskin, John, 1819-1900. (["Box 31"])(undated)[Mathematical problem - autograph manuscript, likely by Ruskin.]. https://collections.library.yale.edu/catalog/2020260.