29.08.1882 Frege to Anton Marty (XII/1)
09.09.1882 Carl Stumpf to Frege (XVI/1)
24.05.1891 Frege to Edmund Husserl (VII/1)
18.07.1891 Edmund Husserl to Frege (VII/2)
after1891? Frege to Giuseppe Peano (XIV/1)
30.01.1894 Giuseppe Peano to Frege (XIV/2)
10.02.1894 Giuseppe Peano to Frege (XIV/3)
11.02.1894 Moritz Pasch to Frege (XIII/1)
20.01.1895 L. Eugene Ballue to Frege (I/1)
09.02.1895 L. Eugene Ballue to Frege (I/2)
14.08.1895 Giuseppe Peano to Frege (XIV/4)
01.10.1895 Frege to David Hilbert (IV/1)
04.10.1895 David Hilbert to Frege (IV/2)
24.10.1895 Giuseppe Peano to Frege (XIV/5)
05.04.1896 Giuseppe Peano to Frege (XIV/6)
29.09.1896 Frege to Giuseppe Peano (XIV/7)
9/10?.1896 Giuseppe Peano to Frege (XIV/8)
03.10.1896 Giuseppe Peano to Frege (XIV/9)
14.10.1896 Giuseppe Peano to Frege (XIV/10)
undated Frege to Giuseppe Peano (XIV/11)
14.10.1896 Moritz Pasch to Frege (XIII/2)
21.10.1896 L. Eugene Ballue to Frege (I/3)
03.01.1897 L. Eugene Ballue to Frege (I/4)
15.04.1897 L. Eugene Ballue to Frege (I/5)
01.07.1899 Louis Couturat to Frege (II/1)
08.07.1899 Louis Couturat to Frege (II/2)
14.11.1899 Moritz Pasch to Frege (XIII/3)
27.12.1899 Frege to David Hilbert (IV/3)
29.12.1899 David Hilbert to Frege (IV/4)
06.01.1900 Frege to David Hilbert (IV/5)
15.01.1900 David Hilbert to Frege (IV/6)
29.07.1900 Frege to Heinrich Liebmann (X/1)
25.08.1900 Frege to Heinrich Liebmann (X/2)
16.09.1900 Frege to David Hilbert (IV/7)
22.09.1900 David Hilbert to Frege (IV/8)
06.01.1901 Louis Couturat to Frege (II/3)
18.06.1901 Louis Couturat to Frege (II/4)
13.10.1901 Louis Couturat to Frege (II/5)
1902 Frege to Edward V. Huntington (VI/1)
16.06.1902 Bertrand Russell to Frege (XV/1)
22.06.1902 Frege to Bertrand Russell (XV/2)
24.06.1902 Bertrand Russell to Frege (XV/3)
29.06.1902 Frege to Bertrand Russell (XV/4)
10.07.1902 Bertrand Russell to Frege (XV/5)
24.07.1902 Bertrand Russell to Frege (XV/6)
28.07.1902 Frege to Bertrand Russell (XV/7)
03.08.1902 Frege to Bertrand Russell (XV/8)
08.08.1902 Bertrand Russell to Frege (XV/9)
07.09.1902 Philip E. B. Jourdain to Frege (VIII/1)
23.09.1902 Frege to Philip E. B. Jourdain (VIII/2)
23.09.1902 Frege to Bertrand Russell (XV/10)
29.09.1902 Bertrand Russell to Frege (XV/11)
20.10.1902 Frege to Bertrand Russell (XV/12)
12.12.1902 Bertrand Russell to Frege (XV/13)
28.12.1902 Frege to Bertrand Russell (XV/14)
07.01.1903 Giuseppe Peano to Frege (XIV/12)
18.01.1903 Moritz Pasch to Frege (XIII/4)
20.02.1903 Bertrand Russell to Frege (XV/15)
21.05.1903 Frege to Bertrand Russell (XV/16)
24.05.1903 Bertrand Russell to Frege (XV/17)
21.06.1903 Alwin Reinhold Korselt to Frege (IX/1)
27.06.1903 Alwin Reinhold Korselt to Frege (IX/2)
30.06.1903 Alwin Reinhold Korselt to Frege (IX/3)
07.11.1903 David Hilbert to Frege (IV/9)
11.02.1904 Louis Couturat to Frege (II/6)
17.03.1904 Giovanni Vailati to Frege (XVII/1)
21.03.1904 Frege to Philip E. B. Jourdain (VIII/3)
22.03.1904 Philip E. B. Jourdain to Frege (VIII/4)
13.11.1904 Frege to Bertrand Russell (XV/18)
12.12.1904 Bertrand Russell to Frege (XV/19)
07.01.1905 Moritz Pasch to Frege (XIII/5)
21.10.1906 Louis Couturat to Frege (II/7)
30.10-01.11.1906 Frege to Edmund Husserl (VII/3)
13.11.1906 Moritz Pasch to Frege (XIII/6)
09.12.1906 Frege to Edmund Husserl (VII/4)
28.01.1909 Philip E. B. Jourdain to Frege (VIII/5)
15.02.1909 Philip E. B. Jourdain to Frege (VIII/6)
16.04.1910 Philip E. B. Jourdain to Frege (VIII/7)
23.04.1910 Philip E. B. Jourdain to Frege (VIII/8)
undated Frege to Philip E. B. Jourdain (VIII/9)
09.06.1912 Frege to Bertrand Russell (XV/20)
29.03.1913 Philip E. B. Jourdain to Frege (VIII/10)
15.01.1914 Philip E. B. Jourdain to Frege (VIII/11)
??.01.1914 Frege to Philip E. B. Jourdain (VIII/12)
28.01.1914 Frege to Philip E. B. Jourdain (VIII/13)
31.01.1917 Frege to Hugo Dingler (III/1)
02.02.1917 Hugo Dingler to Frege (III/2)
06.02.1917 Frege to Hugo Dingler (III/3)
26.02.1917 Hugo Dingler to Frege (III/4)
27.06.1917 Hugo Dingler to Frege (III/5)
04.07.1917 Frege to Hugo Dingler (III/6)
10.07.1917 Hugo Dingler to Frege (III/7)
21.07.1917 Frege to Hugo Dingler (III/8)
01.08.1917 Frege to Hugo Dingler (III/9)
17.11.1918 Frege to Hugo Dingler (III/10)
undated Frege to Karl Zsigmondy (XVIII/1)
24.08.1919 Frege to Paul F. Linke (XI/1)
24.04.1925 Richard Hönigswald to Frege (V/1)
26.04-04.05.1925 Frege to Richard Hönigswald (V/2)