The paper of the collaborators of “Function Theory” department Vugar Ismayilov and Rashid Aliyev ‘On a smoothness problem in Ridge function representation” was published in “Advances in Applied Mathematics” journal, 2016, vol. 73. The paper was devoted to the paper of the known specialist in approximation theory A.Pinkus and M.Buhmann “Smoothness of Ridge functions representation”. The solution of this problem was given within some conditions. For the problem statement and the paper you can see http://www.sciencedirect.com/science/article/pii/S0196885815001281.