@book{TheArtOfProlog,
     Author = "Sterling, Leon and Shapiro, Ehud",
     Title = "The Art of Prolog",
     Publisher = "MIT Press",
     Year = "1986"	}

@Book{ProgrammingInProlog,
	Author       ="William F. Clocksin and Christopher S. Mellish",
	Title        ={Programming in Prolog},
	Publisher    ={Springer-Verlag},
	Year         =1986
}