1. http://cdn.intechopen.com/pdfs-wm/37900.pdf
2. http://education.mrsec.wisc.edu/documents/usingVectors-_answers.pdf
3. http://myukk.xsrv.jp/free_journal/download.php?fn=NDFCT511_full.pdf
4. http://www.researchgate.net/profile/Yoshinori_Ando/publication/42804843Chemical_Vapor_Deposition_of_Carbon_Nanotubes_A_Review_on_Growth_Mechanism_and_Mass_Production/links/0fcfd50809726e590a000000.p
5. http://www.understandingnano.com/electrical-properties-carbon-nanotubes.html