I've never heard "de você(s)" to mean "your(s)", but teu(s),tua(s),seu(s),sua(s),vosso(s),vossa(s). We do have 2 useful contractions of this type: dele (de+ele) and dela (de+ela). De você(s) seems "about/of you" to me.
Can we say 'O livro e o seu?' or is the'o' wrong? Does it actually change the meaning from ' the book is yours' to 'the book is your one' ? which is similar meaning except the second sentence implies there are more than one books..