Gonzalez, Laura Katalina; Rugeles, Laura Natalia  and  Magnitskiy, Stanislav. Effect of different sources of nitrogen on the vegetative growth of Andean blueberry (Vaccinium méridionale Swartz). Agron. colomb. vol.36, n.1, pp.58-67. ISSN 0120-9965.  https://doi.org/10.15446/agron.colomb.v36n1.69304. Effect of different sources of nitrogen on the vegetative growth of Andean blueberry (Vaccinium méridionale Swartz) (scielo.org.co)