How you cite Minitab software depends upon the editorial style required by your academic program. Many universities require students to follow APA style, but that may not be true of your institution. Other frequently accepted style guides include the Chicago Manual of Style and the MLA Style Manual and Guide to Scholarly Publishing.
The following guideline is based on APA style:
Citing computer software
Arend, Dominic N. (1993). Choices (Version 4.0) [Computer software]. Champaign, IL: U.S. Army Corps of Engineers Research Laboratory. (CERL Report No.CH7-22510)
"If an individual(s) has proprietary rights to the software, their name(s) are listed at the head of the entry, last names first, followed by a period. Otherwise, treat such references as unauthored. Do not italize the title. Specify in brackets that the source is computer software, program or language. List the location and the organization's name that produced the program. Add any other necessary information for identifying the program (in this example, the report number) in parentheses at the entry's conclusion. To reference a manual, follow the same as above but add "manual" as the source in the bracketed information. Do not add a period at the end of a citation if it ends in a web address."
Therefore, following APA style guidelines, Minitab software would be cited:
Minitab 17 Statistical Software (2010). [Computer software]. State College, PA: Minitab, Inc. (www.minitab.com)
Quality Companion 3 by Minitab (2009). [Computer software]. State College, PA: Minitab, Inc. (www.minitab.com)
If your institution follows a style manual other than APA, refer to that manual's bibliography section and follow their recommendations.