Actor Akkineni Nagarjuna on Friday announced that directors Kalyan Krishna and Vikram Kumar will direct his sons -- Naga Chaitanya and Akhil -- in their next projects."Sept rocks for me. Announcing films with two of my star directors. Kalyan with Naga Chaitanya. Vikram Kumar with Akhil. On the floors very soon," Nagarjuna wrote on his Twitter page.Interestingly, Nagarjuna had previously worked with Kalyan and Vikram Kumar in "Soggade Chinni Nayana" and "Manam", respectively.Both the projects are slated to go on the floors later this year.Meanwhile, Naga Chaitanya currently awaits the release of "Premam", eponymous Telugu remake of Malayalam blockbuster.