@article{ref1,
title="Trends in agricultural aviation. Assessment of the efficiency of aerial sprays",
journal="Chemistry and industry",
year="1968",
author="Amsden, R. C.",
volume="4",
number="",
pages="108-111",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0009-3068",
doi="",
url="http://dx.doi.org/"
}