Hurd, P. D. (1961). Biological education in American secondary schools, 1890-1960. American Institute of Biological Sciences.
芝加哥风格引文Hurd, Paul DeHart. Biological Education in American Secondary Schools, 1890-1960. Washington: American Institute of Biological Sciences, 1961.
MLA引文Hurd, Paul DeHart. Biological Education in American Secondary Schools, 1890-1960. American Institute of Biological Sciences, 1961.
警告：这些引文格式不一定是100％准确.