@article{LudwigSchmidMarreetal.1991,
  author    = {B. Ludwig and A. Schmid and R. Marre and J{\"o}rg Hacker},
  title     = {Cloning, genetic analysis and nucleotide sequence of a determinant coding for a 19 kd peptidoglycan-associated protein (Ppl) of Legionella pneumophila},
  year      = {1991},
}