1981.
Trademark because it has the "r" with the circle after the title, which means it is federally registered as a trademark. If it was copyrigh, it would have the "c" with the circle.
Symbol for "registered trademark"
The symbol capital R within a circle [®], or circled capital letter R, is the registered trademark symbol. This indicates that the product is registered with a national trademark office (ex: Registered, U.S. Patent and Trademark Office). If a trademark is not officially registered, then it will be marked with a superscript TM (in capitals).
the ® means Registered Trademark
A little R in a circle usually means "registered trademark".
The ® symbol can be used after a business name that has been registered as a trademark.
The registered trademark symbol, an R in a circle, indicates the preceding logo, slogan, etc. has been formally registered; the trademark symbol, a superscript TM, indicates the mark has not been formally registered.
Use of the TM and SM symbols may be governed by local, state, or foreign laws and the laws of a pertinent jurisdiction to identify the marks that a party claims rights to. The federal registration symbol, the R enclosed within a circle, may be used once the mark is actually registered in the USPTO. Even though an application is pending, the registration symbol may not be used before the mark has actually become registered. The federal registration symbol should only be used on goods or services that are the subject of the federal trademark registration. PLEASE NOTE: Several foreign countries use the letter R enclosed within a circle to indicate that a mark is registered in that country. Use of the symbol by the holder of a foreign registration may be proper.
The little TM symbol in a circle represents a trademark. It indicates that the word, phrase, logo, or symbol that it is associated with has been registered as a trademark to protect it from unauthorized use. It signifies ownership and asserts the rights of the trademark owner.
the "r" in a circle is called "Radius". It the same as half of the diameter. ---- A capital R in a circle is a registration mark. It is used to signify registration of a trademark and is placed on a product to signify ownership of the rights to that product.
In parentheses enclose the words "registered trademark."
In geometry it would indicate a radius. More generally, it would indicate a Registered Trademark.