An Analysis of Electrical Impedance Measurements Applied for Plant N Status Estimation in Lettuce (Lactuca sativa). - Rafael F. Muñoz-Huerta; Antonio de J. Ortiz-Melendez; Ramon Gerardo Guevara-Gonzalez; Irineo Torres-Pacheco; Gilberto Herrera Ruiz; Luis Miguel Contreras-Medina; Juan Prado-Olivarez; Rosalia V. Ocampo-Velazquez (Sensors, 2014)