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2. A Treatise on Electricity and Magnetisme, Vols. 1 and 2;Maxwell,1873
3. Matter and Motion;Maxwell,1895
4. Opere. Vol. I. Un. Mat. Ital & Cons. Naz. Ricerche;Ricci-Curbastro,1956
5. Opere. Vol. II. Un. Mat. Ital & Cons. Naz. Ricerche;Ricci-Curbastro,1957