CORRECT: 1) Do you know any books German books about France and vice versa? (Vice versa would be French books about Germany.) INCORRECT: (You haven't provided anything in which to reciprocate the opposite.) 2) Do you want to sleep or vice versa? 3) Does she know already or vice versa? More correct examples: She ended up having a lot of influence on his career, and vice versa. [=and he also ended up having a lot of influence on her career] The camera can adjust for a light subject on a dark background, or vice versa. [=or a dark subject on a light background]