Different author names

[Ysabet]

This book: http://www.goodreads.com/book/show/30...
was publsihed under another author name as this:
http://www.goodreads.com/book/show/30...
but they are the same book and I can´t combine them when there are different authors.
What shall I do?

[Paula]

The name the book was first published under should be used as the primary author name. The name the book was later published under is then added as a secondary author name on appropriate editions.

I have done this and combined