Good morning Moshi. There is something called a poor man's copyright that I've heard of.
I'm NO expert & cannot comment of the actually legalities but I've heard maybe you can protect yourself by sending your works to yourself via certified mail then storing it away unopened.
Hm, really? Maybe I'll look into that... and look into selling some of my artwork so I can afford various things - job markets just don't account for the deaf-who-know-no-sign-language. (Okay, I can say "I love you" and "Jesus" without fingerspelling.....)
Hehe.
~Moshi-chan