Engert, M. (1969). Problems of Long-term Planning in the German Democratic Republic. The Institute of National Planning.
芝加哥风格引文Engert, Manfred. Problems of Long-term Planning in the German Democratic Republic. Cairo: The Institute of National Planning, 1969.
MLA引文Engert, Manfred. Problems of Long-term Planning in the German Democratic Republic. The Institute of National Planning, 1969.
警告：这些引文格式不一定是100％准确.