Berkman, E. T., & Reise, S. P. (2012). Descriptive statistics. In A Conceptual Guide to Statistics Using SPSS (pp. 5-18). SAGE Publications, Inc., https://doi.org/10.4135/9781506335254 Read Chapters 3 and 15.
Keith McCormick, Jesus Salcedo, & Aaron Poh. (2015). SPSS Statistics for Dummies: Vol. 3rd edition. For Dummies. Review as needed for the Signature Assignment.