MLA

Ludlow, H. G. (Henry Gilbert), 1797-1867. Submission to God, Psalm xxxix, 9 : a sermon, preached at the funeral of Mrs. Caroline E. Lathrop, wife of Mr. Alvan Lathrop, who died at Poughkeepsie, N.Y. Thursday, February 27, 1845, at 1-4 before 5, A.M. and was buried March 1st, 1845. [1845?]. https://collections.library.yale.edu/catalog/32304209.

APA, 6th edition

Ludlow, H. G. (Henry Gilbert), 1797-1867. ([1845?])[Submission to God, Psalm xxxix, 9 : a sermon, preached at the funeral of Mrs. Caroline E. Lathrop, wife of Mr. Alvan Lathrop, who died at Poughkeepsie, N.Y. Thursday, February 27, 1845, at 1-4 before 5, A.M. and was buried March 1st, 1845]. https://collections.library.yale.edu/catalog/32304209.