@article{romera2008drawing,
  title = {Drawing and computing external rays in the multiple-spiral medallions of the Mandelbrot set},
  author = {Romera, M and Alvarez, Gonzalo and Arroyo, David and Orue, AB and Fernandez, Veronica and Pastor, G},
  journal = {Computers \& Graphics},
  volume = {32},
  number = {5},
  pages = {597--610},
  year = {2008},
  publisher = {Pergamon}
}