Remember Tumble Books from elementary school? Well, they have teen books, including some of the classics you may be using for research papers. Check it out. Included are all levels with passwords in case younger siblings want to access them. There is also math for K-6 students.
tumblebooks.com
K-6 Tumble Books username tumble735, password books
K-6 Tumble Math username tumble2020, password A3b5c6
7-12 Teen BookCloud username tumble2020, password A3b5c6