Takakazu Mori Mariko Yasugi Yoshiki Tsujii Integral of Fine Computable functions and Walsh Fourier series. 279-293 2008 202 Electr. Notes Theor. Comput. Sci. http://dx.doi.org/10.1016/j.entcs.2008.03.021 db/journals/entcs/entcs202.html#MoriYT08