Array ( [0] => Array ( [title] => L21A [link] => https://www.youtube.com/embed/a624o4RAIlU ) [1] => Array ( [title] => L21B [link] => https://www.youtube.com/embed/ygvCXggqAdQ ) [2] => Array ( [title] => L21C [link] => https://www.youtube.com/embed/h_uxrYz6uzg ) ) 國立清華大學開放式課程OpenCourseWare(NTHU, OCW) - 第21R講 Geodesic Equations