Relativistic center-of-mass variables and the Harmonic oscillator quark model calculation of the nucleon magnetic moment and the axial-vector coupling constant: A. Ilakovac and D. Tadic. Zavod za Teorijsku Fiziku, Prirodoslovno-Matematički Fakultet, University of Zagreb, Zagreb. Croatia, Yugoslavia; F. A. B. Coutinho. Instituto de Física, Universidade de Sao Paulo, Sao Paulo, Brazil; and F. Krmpotić. Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina