BARTH, K. F., & BRANNAN, D. A. (1996). ASYMPTOTIC TRACTS OF HARMONIC FUNCTIONS III. International Journal of Mathematics and Mathematical Sciences, 1996(), 633-636. https://doi.org/10.1155/S0161171296000890
STANKOVIC, B. (1992). ASYMPTOTICS OF REGULAR CONVOLUTION QUOTIENTS. International Journal of Mathematics and Mathematical Sciences, 1992(), 631-634. https://doi.org/10.1155/S0161171292000838