There are good books of very reputable Russian historian-archaeologist B.A.Rybakov (Б.А.Рыбаков) regard the topic. One of them a folio "Язычество древних славян" (Heathendom of ancient Slavs) - about the pre-Christian Slavic history and even prehistory (since paleolith). It's a pity my English is far far from good and I'm afraid writing something sensible about that in English is beyond my abilities - too many specific terms.

The autochthonic theory considers archaeological levels of tshinecko-komarovskaya culture (term?) (1400-1300 B.C.), pshevorskaya and zarubinetskaya culture (300 B.C. - 300 A.D.), and culture of Praga-Korchack type (500-800 A.D.) as Slavic. All these archaeological cultures are in Oder, Vistula, and Dnieper river basins.