Ok so in the book series by erin hunter called warriors when does SIGH OF THE MOON coming out any one know plz?

ok so i've read the whole series in order all thew field guides and special edition book a real fan of warriors i'm in the middle of book 3 of omen of the starrs night whispers i need to know when sigh of the moon comes out and if u know when CROOKEDSTARS PROMISE COMES OUT TO PLEASE