@article{69620,
      recid = {69620},
      author = {Norville, Warren.},
      title = {Celestial navigation step by step.},
      publisher = {International Marine Pub. Co.},
      address = {Camden, Me.,},
      pages = {157 p.},
      year = {1973},
      url = {http://library.usi.edu/record/69620},
}