@article {MATHEDUC.06140171,
    author       = {Stephenson, Paul},
    title        = {The 4-square computer.},
    year         = {2012},
    journal      = {SYMmetryplus},
    number       = {47},
    issn         = {1464-7060},
    pages        = {11-13},
    publisher    = {The Mathematical Association (MA), Leicester},
    abstract     = {From the introduction: The ancients asserted, though it was not proved until 1770, that you can write every positive integer as the sum of no more than 4 squares. We can use this result and two more known to the ancients: the angle in a semicircle is a right angle and Pythagoras' theorem, to design an analog computer to partition every number into squares.},
    msc2010      = {F60xx (G40xx)},
    identifier   = {2013b.00552},
}