Complex sentence: Later, while attending McMaster University in Hamilton, Ontario, where he received a Bachelor of Science degree, he began to use his initials, "PJ", and his books are published under the name "PJ Haarsma".
Split into simpler sentences: Later, while attending McMaster University in Hamilton, Ontario, where Haarsma received a Bachelor of Science degree, he began to use "PJ". His books are published under the name "PJ Haarsma".