Complex sentence: The YA novel, published in 1974, sold out its 45,000-copy print run in four months, and she wrote two bestselling sequels, "Mini-Bike Racer" and "Mini-Bike Rescue" following the success of her first book.
Split into simpler sentences: The YA novel, published in 1974, sold out its 45,000-copy print run in four months. Mackay wrote two bestselling sequels, "Mini-Bike Racer"and "Mini-Bike Rescue" following the success of her first book.