SELECT T1.Writer FROM book AS T1 JOIN publication AS T2 ON T1.Book_ID  =  T2.Book_ID WHERE T2.Price  >  4000000
Show writers who have published a book with price more than 4000000.
[Schema (values) (types)]: | book_2 |  publication : publication_id (text) , book_id (number) , publisher (number) , publication_date (text) , price (text) | book : book_id (text) , title (number) , issues (number) , writer (text);