By A Mystery Man Writer
Blue whales sing in ever lower pitch
Mystery of whale song unraveled by scientists, study says
Whale songs' changing pitch may be response to population, climate changes - AGU Newsroom
media./assets/img/2015/08/05/humpbackwhales
Blue whales worldwide singing little flat: Study - Times of India
Whales Smithsonian Ocean
List 9+ How Loud Is A Blue Whale Detail
JMSE, Free Full-Text
Priceless poo: the global cooling effect of whales