@ARTICLE {5546,
author={F. Martins},
doi={},
journal={Far East Journal of Mathematical Education},
title={Conjugacy and Geometry I - Foot of the Perpendicular, Distance and Gram Determinant (C. Costa, F. Martins, R. Serôdio, P. Tadeu, M. A. Facas Vicente and J. Vitória)},
year={2009},
month={October},
volume={3},
number={3},
pages={235-262},
ISSN={0973-5631}
}