Per Year

 @incollection{modallogic-handbookphilologic1984,
    address = {Dordrecht},
    author = {Bull, Robert and Segerberg, Krister},
    booktitle = {Handbook of Philosophical Logic},
    doi = {10.1007/978-94-009-6259-0_1},
    editor = {Gabbay, Dov and Guenthner, F.},
    isbn = {978-94-009-6259-0},
    pages = {1--88},
    publisher = {Springer Netherlands},
    title = {Basic Modal Logic},
    url = {http://link.springer.com/10.1007/978-94-009-6259-0_1},
    volume = {II: Extensions of Classical Logic},
    year = 1984
} 

 @book{lloyd-lpbook1984,
	Author = {Lloyd, John W.},
	Edition = {1st},
	Isbn = {3-540-13299-6},
	Publisher = {Springer},
	Title = {Foundations of Logic Programming},
	Year = 1984}