Per anno

@incollection{linedrawings-pcv1975,
    apice = {LinedrawingsPcv1975},
    author = {David L. Waltz},
    booktitle = {The Psychology of Computer Vision},
    editor = {Patrick Henry Winston},
    isbn13 = {978-0-07-071048-6},
    location = {New York, NY, USA},
    numpages = 73,
    pages = {19--91},
    publisher = {McGraw-Hill},
    title = {Understanding Line Drawings of Scenes with Shadows},
    year = 1975
}