@article{PNA_2009_2009_1_a7,
     author = {Camacho, Mat{\'\i}as and  Perdomo-D{\'\i}az, Josefa and  Santos-Trigo, Manuel},
     title = {Revisiting {University} {Students{\textquoteright}} {Knowledge} that {Involves} {Basic} {Differential} {Equation} {Questions.}},
     journal = {PNA},
     pages = {123-133},
     publisher = {mathdoc},
     volume = {3},
     number = {3},
     year = {2009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PNA_2009_2009_1_a7/}
}