Links to HathiTrust digitized books are available only on the records of print books the BU Libraries own.
For books/ebooks, filtering for "Available online" will not retrieve HathiTrust digitized books.
Digitized articles in library print journals may require finding the journals in HathiTrust. The easiest way is to find a journal is by the ISSN found in a journal's record, e.g. Identifier </b>ISSN: </b> : 0003-9853. Use the filter for publication date of your article.