How to cite RegScan?

Ponomarenko M.P., Ponomarenko J.V., Frolov A.S., Podkolodnaya O.A., Vorobyev D.G., Kolchanov N.A., Overton G.C. (1999) Oligonucleotide frequency matrices addressed to recognising functional DNA sites. Bioinformatics, 15, 7/8, 631-643.