@article{RuehlSassNauetal.2001,
  author    = {Ralph R{\"u}hl and J{\"o}rn Oliver Sass and Heinz Nau and Stephan Klug},
  title     = {Effects of all-trans-retinoic acid and all-trans-retinoyl glucuronide in two in vitro systems of distinct biological complexity},
  year      = {2001},
}