isbm_goom
is a command line script. Is that what you want?! (you cannot use it in your code like that!)
I suggests you use the most recent version of isbntools
and adapt this snipet
from isbntools.contrib.modules.goom import goom
from isbntools.dev.fmt import fmtbib
...
titledata = goom.query(form.vars.title)
for r in titledata:
print((fmtbib('bibtex', r)))