1. Alonso, J.I., 1998. Estudio del contenido y distribución de los metales pesados en suelos de Navarra: cadmio, cobre, manganeso, niquel, plomo y cinc. Doctoral thesis, Universidad de Navarra
2. Anonymous, 1994–1997. Coyuntura agraria. Departamento de Agricultura, Ganaderı́a y Alimentación, Government of Navarre
3. Anonymous, 1997. Results of large-scale foliar chemistry surveys (survey 1995 and data from previous years). In: Forest Foliar Condition in Europe. UN/ECE, Austrian Federal Forest Research Centre
4. Investigations on nutrient content in beech (Fagus sylvatica L.) seedlings of various provenances;Bidló;Agrokémia És Talajtan,1998
5. Interception and uptake of NH4 and NO3 from wet deposition by above-ground parts of young beech (Fagus sylvatica L.) trees;Brumme;Plant and Soil,1992