ORANGE EDUCATION. (2017). HEIDI - GRADED READER - LEVEL 2. V CONNECT.
芝加哥风格引文ORANGE EDUCATION. HEIDI - GRADED READER - LEVEL 2. NEW DELHI: V CONNECT, 2017.
MLA引文ORANGE EDUCATION. HEIDI - GRADED READER - LEVEL 2. V CONNECT, 2017.
警告：这些引文格式不一定是100％准确.