Below you will find a complete set of details for 2 different references / citations that are related to the computation of type 2 error rates (false negative rates) for t-tests.

Reference for Citing the Online Calculator

- Soper DS. t-Test Type 2 Error Rate (Beta) Calculator [Online Software]. Available from http://www.analyticscalculators.com. 2019.

Reference from the Scientific Literature

- Cohen J. Statistical power analysis for the behavioral sciences. Lawrence Earlbaum Associates, Hillsdale, NJ. 1988.