SIMORANGKIR, O. (1978). Etika Jabatan O.p. Simorangkir. Yagrat.
Chicago Style (17th ed.) CitationSIMORANGKIR, O.P. Etika Jabatan O.p. Simorangkir. Yagrat, 1978.
MLA引文SIMORANGKIR, O.P. Etika Jabatan O.p. Simorangkir. Yagrat, 1978.
警告：這些引文格式不一定是100％准確.