Gaya APA

Geograpic, N., Boyer, C. (2016). Mengapa ? 1.111 pertanyaaan dan jawaban (1). Washington Dc: National Geograpic.

Gaya MLA

Geograpic, N., Boyer, C.. Mengapa ? 1.111 pertanyaaan dan jawaban. 1 Washington Dc: National Geograpic, 2016. Text.