Frobel, F., Michaelis, E., & Moore, H. K. (1891). Froebel's letters on the kindergarten. Swan Sonnenschein.
芝加哥风格引文Frobel, Friedrich, Emilie Michaelis, 与 H. Keatley Moore. Froebel's Letters on the Kindergarten. London: Swan Sonnenschein, 1891.
MLA引文Frobel, Friedrich, et al. Froebel's Letters on the Kindergarten. Swan Sonnenschein, 1891.
警告：这些引文格式不一定是100％准确.