Grechnev, G.; Scharff, P.; Ritter, U.; Grybova, M.; Prylutskyy, Y.; Matzui, L.; Panfilov, A.; Fedorchenko, A.; Desnenko, V.; Kolesnichenko, Y. Structure and Magnetic Properties of Multi-Walled Carbon Nanotubes Modified With Iron. Fiz. Nizk. Temp. 2010, 36, 1347-1351.