Reference:

dBSTAT [computer program]. Version 5. Seoul, Korea: dBSTAT Software, Inc.; 2015. Available from: http://www.dbstat.com/.

According to citing medicine.
Patrias, Karen. Citing medicine: the NLM style guide for authors, editors, and publishers [Internet]. 2nd ed. Wendling, Daniel L., technical editor. Bethesda (MD): National Library of Medicine (US); 2008. Available from: http://www.nlm.nih.gov/citingmedicine