Work cat.: Odom, T.W. Electronic properties of single-walled carbon nanotubes, 2000.

Keller, H. Dictionary of engineering materials, 2004 (nanotubes -- A relatively new class of one-dimensional nanostructured materials including carbon nanotubes and inorganic nanotubes)

Minerals as advanced materials II, 2012: p. 59 (The term "nanotube" does not have a clear-cut definition. In general understandings it describes a nanoscale tube-like structure which can be found naturally in some minerals or be man-made from a variety of materials. The majority of known nanotubes are still carbon nanotubes, but various types and structures of non-carbon nanotubes ... have also been synthesized)

Advanced materials, May 1996: p. 444 (Nanotube formation is not limited to carbon; it appears to be a general feature of layered materials. Several new classes of nanotubes have been predicted and synthesized)

Physica. E, Low-dimensional systems & nanostructures, Mar. 2012: p. 922 (Nanotubes of various non-carbon materials have been produced and characterised. Theoretical modelling of these structures continues to reveal fascinating attributes)

INSPEC.

Proceedings of the School and Workshop on Nanotubes & Nanostructures, c2001.

Web. 3; NASA; Acad. Press dict. of sci. and tech.