:

  •  
                                                          

    ()

    ()

    1 1000 . 1/700 . (. . ). : (N 1), (N 2), (N 3), (N 4), , , , .

    (Appennino)
    (Barquisimeto)
    (Williams) (1883-1962)

    ( . akustikos - )
    :