Found 2 documents matching "substantial source":
http://www.oilwatch.org/doc/boletin/bole60en.pdf
from energy crops requires more fossil fuel energy than they yield, and they do not substantially reduce greenhouse gas emissions
when all the inputs are accounted for. Furthermore, they cause irreparable damages to the soil and the …
http://www.dni.gov/nic/PDF_GIF_2020_Support/2004_04_28_papers/summary.pdf
the views of the US Government Terrorism has taken up a large part of the discussions. It was a
substantial source
of dispute:
some worried about its coming (see above), others warned that too much attention has been paid to this issue, and even …