Rare Books

Carl Friedrich Gauss' untersuchungen über höhere arithmetik : (Disquistiones arithmeticae. Theorematis arithmetici demonstratio nova. Summatio quarumdam serierum singularium. Theorematis fundamentalis in doctrina de residuis quadraticis demonstrationes et amplicationes novae. Theoria residuorum biquadraticorum, commentatio prima et secunda, etc.)