@book {
    title = {test title},
    author = {bob},
    year = {1984},
}
@book {
    title = {test title},
    author = {joe},
    year = {1984},
}
@book {
    title = {test title},
    author = {susan},
    year = {1984},
}
@book {
    title = {test title 2},
    author = {bob},
    year = {1984},
}