Complex sentence: Harold Jones (1904--1992) was a British artist and both illustrator and writer of children's books; critic Brian Alderson called him "perhaps the most original children's book illustrator of the period".
Split into simpler sentences: Harold Jones (1904--1992) was a British artist and both illustrator and writer of children's books. Critic Brian Alderson called him "perhaps the most original children's book illustrator of the period".