International Federation of Organic Agriculture Movements (IFOAM). IFOAM Internal Letter. Tholey-Theley: IFOAM.
Citazione stile Chigago Style (17a edizione)International Federation of Organic Agriculture Movements (IFOAM). IFOAM Internal Letter. Tholey-Theley: IFOAM.
Citatione MLA (8a ed.)International Federation of Organic Agriculture Movements (IFOAM). IFOAM Internal Letter. Tholey-Theley: IFOAM.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.