Complex sentence: In 1971, she wrote "La brume de Philadelphie" for Petula Clark, which was issued as the B-side of Clark's French single "La Chanson de Marie Madeleine".
Split into simpler sentences: In 1971, she wrote "La brume de Philadelphie" for Petula Clark. The song was issued as the B-side of Clark's French single "La Chanson de Marie Madeleine".