연구
Mercury -- from Eric Weisstein's World of Astronomy
http://scienceworld.wolfram.com/astronomy/Mercury.html
수성의 관측
http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=mb&sstr=1
http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=mb&sstr=1
궤도와 회전
Comptes rendus hebdomadaires des séances de l'Académie des sciences : Académie des sciences (France) : Free Download, Borrow, and Streaming : Internet Archive
http://www.archive.org/stream/comptesrendusheb49acad#page/378/mode/2up