If you would like to cite any of the software tutorials, you may use the following information.
Example APA-style citations:
Kent State University Libraries. (2017, May 15). SPSS tutorials: Independent samples t test. Retrieved May 17, 2017, from http://libguides.library.kent.edu/SPSS/IndependentTTest
Kent State University Libraries. (2017, May 22). SAS tutorials: Subsetting and splitting datasets. Retrieved May 23, 2017, from http://libguides.library.kent.edu/SAS/SubsetData