It would be helpful to be able to toggle between a text book and its related answer key and/or workbook. At the moment there is nothing to remind the user that the other piece exists.
Long, Fredrick J. Kairos: a Beginning Greek Grammar. Mishawaka, IN: Fredrick J. Long, 2005. AND Long, Fredrick J. Workbook for Kairos: a Beginning Greek Grammar. Mishawaka, IN.: Fredrick J. Long, 2005. AND Long, Fredrick J. Answer Key and Guide for Kairos: a Beginning Greek Grammar with an Accompanying Workbook. Mishawaka, IN.: Fredrick J. Long, 2007.
Nunn, H. P. V. The Elements of New Testament Greek. Cambridge: Cambridge University Press, 1923. AND Nunn, H. P. V. Key to The Elements of New Testament Greek. Bellingham, WA: Logos Bible Software, 2003.
