The paper Polymer X-ray refractive nano-lenses fabricated by additive technology written by A. K. Petrov, V. O. Bessonov, K. A. Abrashitova, N. G. Kokareva, K. R. Safronov, A. A. Barannikov, P. A. Ershov, N. B. Klimova, I. I. Lyatun, V. A. Yunkin, M. Polikarpov, I. Snigireva, A. A. Fedyanin, and A. Snigirev has been published in Optics Express.