APA
Gupta D. P. S., National Council of Educational Research and Training (New Delhi), Gujjarappa B. G. (. & Mandol S. (. (1989). What on earth is energy. New Delhi: National Council of Educational Research and Trainings.
Chicago
Gupta D P Sen, National Council of Educational Research and Training (New Delhi), Gujjarappa B G (Ill.) and Mandol Samir (Ill.). 1989. What on earth is energy. New Delhi: National Council of Educational Research and Trainings.
Harvard
Gupta D. P. S., National Council of Educational Research and Training (New Delhi), Gujjarappa B. G. (. and Mandol S. (. (1989). What on earth is energy. New Delhi: National Council of Educational Research and Trainings.
MLA
Gupta D P Sen, National Council of Educational Research and Training (New Delhi), Gujjarappa B G (Ill.) and Mandol Samir (Ill.). What on earth is energy. New Delhi: National Council of Educational Research and Trainings. 1989.
