Greet for everyone in this forum, i am looking for papers because i need it so much.. if anyone has them or may guide me to their link, please send it to me and i will be very grateful for him... papers as follows: 1-A.A. Khachatryan, "Longitudinal vibrations of prismatic bars made of different-modulus materials,[/B]" Mech. solids, 2(5), pp.94-97, 1967. 2-A.G. Galoyan and A.A. Khachatryan,"On transversal vibration of beams made from different modulus material[/B]," (in Russian), Dokl. akad. nauk Armyanskoi SSR, 66, 22-26 (1978). see Appl. mech. rev., 32, Rev. 1055 (1979).