Gaya APA
Espig, Gustav, Lubis, Mochtar, Suherly, Lily. (1988).
Ekologi .
Jakarta:
Yayasan Obor Indonesia.
Gaya Chicago
Espig, Gustav, Lubis, Mochtar, Suherly, Lily.
Ekologi.
Jakarta:
Yayasan Obor Indonesia,
1988.
Text.
Gaya MLA
Espig, Gustav, Lubis, Mochtar, Suherly, Lily.
Ekologi.
Jakarta:
Yayasan Obor Indonesia,
1988.
Text.
Gaya Turabian
Espig, Gustav, Lubis, Mochtar, Suherly, Lily.
Ekologi.
Jakarta:
Yayasan Obor Indonesia,
1988.
Print.