kaufman, J. (2013). The first 20 hours: How to learn anything fast. Portfolio Penguin.
Chicagoスタイル(17版)引用形式kaufman, Josh. The First 20 Hours: How to Learn Anything Fast. London: Portfolio Penguin, 2013.
MLA(9版)引用形式kaufman, Josh. The First 20 Hours: How to Learn Anything Fast. Portfolio Penguin, 2013.
警告: この引用は必ずしも正確ではありません.