When a person writes an article or book about a living person, the author has to deal with issues like publicity rights, rights to privacy, moral rights, and defamation. If I'm not mistaken, these rights do not apply to deceased people, however.
On the other hand, some people are protected by "estate rights." (I'm not sure if that's the proper term.) Examples include Jimi Hendrix, Elvis Presley, and Albert Einstein.
Here's my question: How can an author determine if a deceased person they want to write about is protected by estate rights or some other special kind of protection?