[1] Prior to joining Peking University, Song held visiting faculty positions at Boston College in Massachusetts and Tokyo Institute of Technology in Japan.
[2] Song is the author of Lattice Path Combinatorics and Special Counting Sequences: From an Enumerative Perspective, CRC Press, Boca Raton, ISBN 978-1032671758.
Coauthored with Chen Dayue (陈大岳) and Xu Zhongqin (许忠勤), Song is a main editor of the tribute volume Ding Shisun and Chinese Mathematics (《丁石孙与中国数学》).
He is the author of Heroes Brought Buddhism to the East of the Sea: A Fully Annotated Translation of The Preface of Haedong Kosŭng Chŏn, published in Sino-Platonic Papers (Issue 183).
In 2014, Song gave a talk at Academia Sinica titled The Art of Lattice Path Combinatorics and Combinatorial Statistics.