Droogmans, J. (1959). In memoriam Professor Mr. J.-H.-Paul Bellefroid. S.l.: s.n.
芝加哥风格引文Droogmans, Jozef. In Memoriam Professor Mr. J.-H.-Paul Bellefroid. S.l.: s.n, 1959.
MLA引文Droogmans, Jozef. In Memoriam Professor Mr. J.-H.-Paul Bellefroid. S.l.: s.n, 1959.
警告：这些引文格式不一定是100％准确.