Discuss the Handbook on Aging (HA) Harris, G. J. (2018). A handbook on aging: A multidisciplinary perspective with critical readings (1st ed.) San Diego, CA: Cognella, Inc. (ISBN-13: 978-1516512553) Textbook 2: Main Textbook (HB) Hillier, S., & Barrow, G. M. (2015). Aging, the individual, and society (10th ed.). Stamford, CT: Cengage Learning (ISBN: 13: 978-1-285-74661-6).