@article {IOPORT.50017949,
    author       = {Wulf, William A. and London, Ralph L. and Shaw, Mary},
    title        = {An introduction to the construction and verification of alphard programs},
    year         = {1976},
    journal      = {IEEE Trans. Software Eng.},
    volume       = {2},
    number       = {4},
    pages        = {253-265},
    identifier   = {50017949},
}