Factorization of Lipschitz Functioins and Absolute Convergence of Vilenkin-Fourier Series. Leonard Y.H. Yap; T.S. Quek — 1981 Monatshefte für Mathematik
Sharpness of Young's inequality for convolution. Leonard Y.H. Yap; T.S. Quek — 1983 Mathematica Scandinavica