MLA

Edwards, Jonathan, 1703-1758. 6. Edwards, Timothy. Small book of theological observations and questions, etc.. Box 1, folder 23. Undated. https://collections.library.yale.edu/catalog/33260360.

APA, 6th edition

Edwards, Jonathan, 1703-1758. (["Box 1, folder 23"])(Undated)[6. Edwards, Timothy. Small book of theological observations and questions, etc.]. https://collections.library.yale.edu/catalog/33260360.