APA (7th ed.) Citation

Sitorus, L. (2005). Windows on the World: English for SMA Book 1. Erlangga.

Chicago Style (17th ed.) Citation

Sitorus, Lunguk. Windows on the World: English for SMA Book 1. Erlangga, 2005.

MLA (8th ed.) Citation

Sitorus, Lunguk. Windows on the World: English for SMA Book 1. Erlangga, 2005.

Warning: These citations may not always be 100% accurate.