↑ 1,01,11,2Lide, David R. (1990–1991). CRC Handbook of Physics and Chemistry (ring Inggris) (édisi ka-71st). Boca Raton, Ann Arbor, Boston: CRC Press, inc. pp. 4-22 (one page).
↑Tetrazoles contain a pair of double-bonded nitrogen atoms with oxidation state 0 in the ring. A Synthesis of the parent 1H-tetrazole, CH2N4 (two atoms N(0)) is given in Ronald A. Henry and William G. Finnegan, "An Improved Procedure for the Deamination of 5-Aminotetrazole", _J. Am. Chem. Soc._ (1954), 76, 1, 290–291,
https://doi.org/10.1021/ja01630a086.