Complex sentence: This series of 20 childrens books was published between 1920 and 1950 by George G. Harrap of London was unusual as it involved eight different individual authors working with a single illustrator.
Split into simpler sentences: This series of 20 childrens books was published between 1920 and 1950 by George G. Harrap of London. It was unusual as it involved eight different individual authors working with a single illustrator.