@article{hadwin_1995, 
  title={Triangular truncation and normal limits of nilpotent operators}, 
  volume={123}, 
  DOI={10.1090/s0002-9939-1995-1257109-0}, 
  publisher={American Mathematical Society (AMS)}, 
  author={Hadwin}, 
  year={1995}, 
  month={Jun}
  }