(2001). Portugal, Belgium. OECD Publications Services.
芝加哥风格引文Portugal, Belgium. Paris, France: OECD Publications Services, 2001.
MLA引文Portugal, Belgium. OECD Publications Services, 2001.
警告：这些引文格式不一定是100％准确.
APA引文
(2001). Portugal, Belgium. OECD Publications Services.
芝加哥风格引文Portugal, Belgium. Paris, France: OECD Publications Services, 2001.
MLA引文Portugal, Belgium. OECD Publications Services, 2001.