Organisation for Economic Co-operation and Development. (1990). OECD economic surveys: Belgium - Luxembourg. Organisation for Economic Co-operation and Development.
Чикаго-гийн эшлэл (17 дахь хэвлэлт)Organisation for Economic Co-operation and Development. OECD Economic Surveys: Belgium - Luxembourg. Paris, France: Organisation for Economic Co-operation and Development, 1990.
MLA -ийн эшлэл (9 дэх хэвлэлт)Organisation for Economic Co-operation and Development. OECD Economic Surveys: Belgium - Luxembourg. Organisation for Economic Co-operation and Development, 1990.
Анхааруулга: Эдгээр ишлэлүүд үргэлж 100% үнэн зөв биш байж магадгүй.