Read OSC's new review column from the Rhinoceros Times, Greensboro, NC . Coming in October - Beyond Ender's Game Boxed Set . Includes paperback editions of Speaker for the Dead, Xenocide, and Children of the Mind. AT OSC's original Ender's Game short story is now available online. If you write a manuscript that, point for point, follows an unattributed source, and you try to pass it off as original work, you have probably crossed the line into unethical copying.
Publishers have long memories when it comes to such offenses.
There are many different kinds of sources, and many ways one work can resemble another. So let's consider some of the possible sources of stories, and see what the rules are. Just the facts. You can't copyright facts. You can only copyright the language used to recount those facts.