Crystal structures of 2-aminopyridine citric acid salts: C<sub>5</sub>H<sub>7</sub>N<sub>2</sub> <sup>+</sup>·C<sub>6</sub>H<sub>7</sub>O<sub>7</sub> <sup>−</sup> and 3C<sub>5</sub>H<sub>7</sub>N<sub>2</sub> <sup>+</sup>·C<sub>6</sub>H<sub>5</sub>O<sub>7</sub> <sup>3−</sup>
Acta crystallographica. Section E, Crystallographic communications