According to imdb.com, the names of the "Paper Sisters" are loosely inspired by three famous Hong Kong actresses: Maggie Cheung, Michelle Yeoh and the late Anita Mui.

Furthermore, there were two action movies in which the three actresses formed a secret superheroine team: "Heroic Trio" and "The Executioners". Interestly, in those movies, Maggie Cheung played the youngest and most impulsive heroine, Michelle Yeoh's character was the secretive and careful one, and Anita Mui was the oldest and most sensible. In R.O.D., the roles are reversed.

Thank you to Carl Chavez for this information!