Sagan. Cosmic Apprentice. University of Minnesota Press.
芝加哥风格引文Sagan. Cosmic Apprentice. University of Minnesota Press.
MLA引文Sagan. Cosmic Apprentice. University of Minnesota Press.
警告：这些引文格式不一定是100％准确.
APA引文
Sagan. Cosmic Apprentice. University of Minnesota Press.
芝加哥风格引文Sagan. Cosmic Apprentice. University of Minnesota Press.
MLA引文Sagan. Cosmic Apprentice. University of Minnesota Press.