Pfeiffer, E. Soil fetility: Renewal and preservation: Biodynamic farming and gardening.1.
استشهاد بنمط شيكاغوPfeiffer, Ehrenfried. Soil Fetility: Renewal and Preservation: Biodynamic Farming and Gardening.1.
MLA استشهادPfeiffer, Ehrenfried. Soil Fetility: Renewal and Preservation: Biodynamic Farming and Gardening.1.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.