Helen Reddy, the Australian singer behind feminist anthem 'I Am Woman', has died aged 78, Variety reports. Reddy said she had penned the lyrics for the song - with lines such as "I am woman, hear me roar" and "I am strong, I am invincible, I am woman" - after struggling to find other songs which reflected her pride in being a woman. A sleeper hit, it went on to sell millions of copies worldwide, making Reddy the biggest-selling female artist globally for two years running. Also, she became prominent in the women's liberation movement. Her first hit, 'I Don't Know How to Love Him', was followed by a succession of others including 'Crazy Love', 'Delta Dawn', and 'Angie Baby'.