Walker Sally M. Early Bird Earth Science Soil. Lerner.
芝加哥风格引文Walker Sally M. Early Bird Earth Science Soil. 2010 2010: Lerner.
MLA引文Walker Sally M. Early Bird Earth Science Soil. Lerner.
警告：这些引文格式不一定是100％准确.
APA引文
Walker Sally M. Early Bird Earth Science Soil. Lerner.
芝加哥风格引文Walker Sally M. Early Bird Earth Science Soil. 2010 2010: Lerner.
MLA引文Walker Sally M. Early Bird Earth Science Soil. Lerner.