Gender-less book

Is there any books that use 'they', 'them' and 'theirs' instead of 'he', 'she', 'him', 'her', 'his' and 'hers'?

I wanna see what genders people happen to assign the characters.

>>13
A Comedy of Errors, Act IV, Scene 3:

    There's not a man I meet but doth salute me
    As if I were their well-acquainted friend

Does anything make a person look dumber than complaining about well-established parts of their language as if they were new?