The HeidelGram corpus, more specifically the annotated XML files, are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. (© 2016 Beatrix Busse, Kirsten Gather, Ingo Kleiber)
This means that you are generally free to
if you accept the following terms:
Busse, Beatrix, Kirsten Gather, and Ingo Kleiber (eds.). 2015-. HeidelGram. A Corpus of English Grammar Books between 1550 and 1900. Heidelberg: University of Heidelberg, English Department. https://heidelgram.de
Please note that the CC-BY-SA-NC does not apply to the original source texts.