Johnston, Robert K.; J Walker Smith (2003). Life Is Not Work, Work Is Not Life: Simple Reminders for Finding Balance in a 24-7 World. Council Oak Books. "...the prodigious polymath of the Italian Renaissance. Painter, sculptor, engineer, astronomer, anatomist, biologist, geologist, physicist, architect, philosopher,
humanist."p. 1
Johnston, Robert K.; J Walker Smith (2003). Life Is Not Work, Work Is Not Life: Simple Reminders for Finding Balance in a 24-7 World. Council Oak Books. p. 1
britannica.com
"Renaissance man". Encyclopædia Britannica. Retrieved 23 March 2021.