Tran H. OBSERVING SOLAR ACTIVITY ON 15TH SEPTEMBER 2005 BY TELESCOPE AT HCMC UNIVERSITY OF PEDAGOGY. Science and Technology Development Journal [Internet]. 15Nov.2009 [cited 19May2024];12(17):12-5. Available from: http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/2361