@article{ref1,
title="Observations of the Magnetic Dip, Made at Several Positions, Chiefly on the South-Western and North-Eastern Frontiers of the United States, and of the Magnetic Declination at Two Positions on the River Sabine; In 1840",
journal="Transactions of the American Philosophical Society",
year="1846",
author="Graham, James D.",
volume="9",
number="3",
pages="329-380",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0065-9746",
doi="10.2307/1005362",
url="http://dx.doi.org/10.2307/1005362"
}