Hathi currently supports a few different ways of obtaining bibliographic citations for items in its digital library. 

All can be found by clicking the "Catalog Record" of any HathiTrust title (example below)

You'll then see the following options at top right:

Cite this provides both an APA and an MLA citation to copy/paste as needed. 

Export to Endnote generates a RIS Formatted file for download and use in Endnote; this usually happens seamlessly. 

Hathi Catalog citations also import well into Zotero, if you have this open source citation manager installed on your PC or laptop.