Dybkaer, R. (2001). „UNIT "KATAL" FOR CATALYTIC ACTIVITY (IUPAC Technical Report)”. Pure Appl. Chem. 73 (6): 929. doi:10.1351/pac200173060927.
Matthiesen J, Wendt S, Hansen JØ, Madsen GK, Lira E, Galliker P, Vestergaard EK, Schaub R, Laegsgaard E, Hammer B, Besenbacher F (2009). „Observation of All the Intermediate Steps of a Chemical Reaction on an Oxide Surface by Scanning Tunneling Microscopy”. ACS Nano. 3 (3): 517—526. ISSN1520-605X. PMID19309169. doi:10.1021/nn8008245.
. Nomenclature Committee of the International Union of Biochemistry (NC-IUB). „Units of Enzyme Activity”. Eur. J. Biochem. 97 (2): 319—20. 1979. doi:10.1111/j.1432-1033.1979.tb13116.x.
Matthiesen J, Wendt S, Hansen JØ, Madsen GK, Lira E, Galliker P, Vestergaard EK, Schaub R, Laegsgaard E, Hammer B, Besenbacher F (2009). „Observation of All the Intermediate Steps of a Chemical Reaction on an Oxide Surface by Scanning Tunneling Microscopy”. ACS Nano. 3 (3): 517—526. ISSN1520-605X. PMID19309169. doi:10.1021/nn8008245.
Matthiesen J, Wendt S, Hansen JØ, Madsen GK, Lira E, Galliker P, Vestergaard EK, Schaub R, Laegsgaard E, Hammer B, Besenbacher F (2009). „Observation of All the Intermediate Steps of a Chemical Reaction on an Oxide Surface by Scanning Tunneling Microscopy”. ACS Nano. 3 (3): 517—526. ISSN1520-605X. PMID19309169. doi:10.1021/nn8008245.