@article{engelfriet_schmidt_leeuwen_1980, 
  title={Stack Machines and Classes of Nonnested Macro Languages}, 
  volume={27}, 
  DOI={10.1145/322169.322178}, 
  publisher={Association for Computing Machinery (ACM)}, 
  author={Engelfriet and Schmidt and Leeuwen}, 
  year={1980}, 
  month={Jan}
  }