Leader 1986. Leader, Solomon (May 1986), "What is a Differential? A New Answer from the Generalized Riemann Integral", The American Mathematical Monthly, 93 (5): 348–356, doi:10.2307/2323591, JSTOR2323591
Leader 1986. Leader, Solomon (May 1986), "What is a Differential? A New Answer from the Generalized Riemann Integral", The American Mathematical Monthly, 93 (5): 348–356, doi:10.2307/2323591, JSTOR2323591