RAY, S. (2014). OUR EARTH: A BOOK OF GEOGRAPHY - 4. FRANK EDUCATIONAL AIDS.
芝加哥风格引文RAY, SUMITRA. OUR EARTH: A BOOK OF GEOGRAPHY - 4. FRANK EDUCATIONAL AIDS, 2014.
MLA引文RAY, SUMITRA. OUR EARTH: A BOOK OF GEOGRAPHY - 4. FRANK EDUCATIONAL AIDS, 2014.
警告：这些引文格式不一定是100％准确.