|url=http://books.google.be/books?id=8VcvAQAAIAAJ&q=%22artur+balder%22&dq=%22artur+balder%22&hl=es&ei=S3MvTdqMJ5KGhQeN-KnoCg&sa=X&oi=book_result&ct=result&resnum=4&ved=0CCoQ6AEwAzgK | |url=http://books.google.be/books?id=8VcvAQAAIAAJ&q=%22artur+balder%22&dq=%22artur+balder%22&hl=es&ei=S3MvTdqMJ5KGhQeN-KnoCg&sa=X&oi=book_result&ct=result&resnum=4&ved=0CCoQ6AEwAzgK |