Exploratory Study on the Effectiveness of a Standardized Extract from Ageratina pichinchensis in Patients with Chronic Venous Leg Ulcers - Romero-Cerecero, Ofelia; Zamilpa-Álvarez, Alejandro; Jiménez-Ferrer, Enrique; Tortoriello, Jaime (Planta Medica, 2012)