How to observe and photograph lunar ray ejecta systems - BBC Sky
APOD Retrospective: August 9 - Starship Asterisk*
Amateur Astronomers Exploring The Moon's Tycho Crater - Moon Crater Tycho
Copernicus (hố Mặt Trăng) – Wikipedia tiếng Việt
PSRD:: Lunar Crater Rays
Courses in Astrophotography
Observing the Moon Centre for Astronomical Heritage (CfAH)
How Does Crater Rays Get Their Form and Shape? - Moon Crater Tycho
Our Lovely Moon And we're lucky to have it! Assembled By Ken Mitchell Livermore TOPScience. - ppt download
A guide to the Moon's Copernicus Crater - BBC Sky at Night Magazine
Copernicus (lunar crater) - Wikipedia
Observing Along the Moon's Terminator, Michael Packer
APOD Retrospective: March 5 - Starship Asterisk*
The length of lunar crater rays explained using secondary crater
APOD Retrospective: March 5 - Starship Asterisk*