Original: In 2000, Joel Whitburn, a Billboard Magazine pop music researcher, named her the most successful female songwriter of 1955-99, because she wrote or co-wrote 118 pop hits on the Billboard Hot 100.
Simplified: In 2000, Joel Whitburn, who writes for Billboard Magazine, named her the most successful female songwriter of 1955-99, because she wrote or co-wrote 118 pop hits on the Billboard Hot 100.