Astronomy: The Cosmic Journey , Fourth Edition William K Hartmann, Chris Impey

KOCMOC: Journey of Astronomical Adventures, Apurba Pandey, Muchammad Thoyib

Astronomy: Exploring Time and Space by University of Arizona, taught by Chris Impey

Mechanics: Motion, Forces, Energy and Gravity, from Particles to Planets by UNSW Sydney (The University of New South Wales) taught by Prof. Joe Wolfe, Dr Elizabeth J. Angstmann, Mr Sebastian Fricke

Imagining Other Earths by Princeton University, taught by David Spergel

STUDYING THE HISTORY OF INDONESIAN ASTRONOMY: FUTURE PROSPECTS AND POSSIBILITIES Wayne Orchiston,Journal of Astronomical History and Heritage · January 2017

PLANNING AND DEVELOPMENT OF INDONESIA’S DOMESTIC COMMUNICATIONS SATELLITE SYSTEM PALAPA *,Marwah Daud Ibrahim, Online Journal of Space Communication Issue8: Regional Development: Indonesia Fall, 2004

For (Fig.1), Andrew Z. Colvin / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0), (https://creativecommons.org/licenses/by-sa/3.0)