Who said "Strength isn't loud; it's the quiet voice that persists."?

This quote is attributed to Joan Fontaine.

Strength isn't loud; it's the quiet voice that persists. - Joan Fontaine

"Strength isn't loud; it's the quiet voice that persists."

Joan Fontaine Strength

Actress British-American 1917–2013

"I am my own woman."

"Life is what you make it."

"Success is not final, failure is not fatal."

"Love is the most beautiful thing in the world."

"Strength comes from within."

"A woman should be proud of who she is."

"A strong woman can overcome anything."

"The only thing I'm good at is killing."