Gaya APA

Hawking, Stepen. (). Riwayat sang kala . : .

Gaya Chicago

Hawking, Stepen. Riwayat sang kala. : , . Text.

Gaya MLA

Hawking, Stepen. Riwayat sang kala. : , . Text.

Gaya Turabian

Hawking, Stepen. Riwayat sang kala. : , . Print.