This paper discusses the differences and similarities between the writing styles of Felix Mendelssohn and Fanny Hensel. The focus is on the lieder of the two as this form was important to both of them.
Nation, K. (1998). Felix Mendelssohn and Fanny Hensel: Comparing the Works of These Sibling Composers (Undergraduate honors thesis, University of Redlands). Retrieved from https://inspire.redlands.edu/cas_honors/67