|source_website=https://www.google.com/books/edition/Brains/EXU2AQAAMAAJ?hl=en&gbpv=1&dq=gearhart+%26+hawk+overton&pg=PA27&printsec=frontcover Accessed date: June 27, 2022. | |source_website=https://www.google.com/books/edition/Brains/EXU2AQAAMAAJ?hl=en&gbpv=1&dq=gearhart+%26+hawk+overton&pg=PA27&printsec=frontcover Accessed date: June 27, 2022. |