1. Atti della VII Giornata della misurazione;Cunietti,1989
2. Basic concepts of measurements: treatment of uncertainties in the evaluation of measurements, 7th proposal (draft);DIN 1319, part IV,1984
3. A review of the fundamental concepts of measurements;Finkelstein;Measurement,1984
4. Measuring instruments and the theory of measurement;Gonella,1988