1. AFNOR, (1992a) Soil quality - physical methods - measurement of apparent density of unrepaired soil sample - cylinder method. In: NF ISO 31501. AFNOR, Paris.
2. AFNOR, (1992b) Determination of Ca2+, Mg2+, K+, Na+ cations extractable by ammonium acetate. In: NF ISO 31501. AFNOR, Paris.
3. AFNOR. (1993a). Soil quality — determination of phosphorus soluble in ammonium oxalates solution - Joret - Hébert method. In NF X (pp. 31–161). Paris: AFNOR.
4. AFNOR, (1993b) Chemical methods: determination of organic carbon by oxidation sulphochromic. In: NF X 31109. AFNOR, Paris.
5. AFNOR, (1994a) Qualité du sol: Prétraitement des échantillons pour analyses physico-chimiques. In: NF ISO 11464, AFNOR, Paris.