Perhaps you should try some spelling variations:
model volumetric » modal volumetric, model econometric, based volumetric
volumetric soil » volumetric soft, volumetric smoke, volumetric tools
soil threats » soil treated
iet world » net world, ict world, int world
iot world » post world, lost world, art world

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "2008 ((iet world) OR (iot world)) model volumetric soil threats*".