APA引文

National Geographic Learning. Sustainability. Clifton Park, NY: Delmar Cengage Learning.

Trích dẫn kiểu Chicago

National Geographic Learning. Sustainability. Clifton Park, NY: Delmar Cengage Learning.

MLA引文

National Geographic Learning. Sustainability. Clifton Park, NY: Delmar Cengage Learning.

警告：這些引文格式不一定是100％准確.