There is more than one author with this name in the database, see f.e. John Marsden.

John Marsden was an Australian writer and school principal. He wrote more than 40 books in his career and his books have been translated into many languages. He was especially known for his young adult novel Tomorrow, When the War Began, which began a series of seven books.
Marsden began writing for children while working as a teacher, and had his first book, So Much to Tell You, published in 1987. In 2006, he started an alternative school, Candlebark School, and reduced his writing to focus on teaching and running the school. In 2016, he opened the arts-focused secondary school, Alice Miller School. Both schools are in the Macedon Ranges.