All the Sor studies on this Hebe site are a completely new edition by Brian Jeffery, taken from the new printed Tecla edition of Sor's Complete Studies, Lessons and Exercises for Guitar (Tecla 101). However, for the convenience of students and others who may know some of them by the numbering in Segovia's old edition of them, here is a concordance. The links will take you to the new Hebe edition.
Segovia Study No.1 = Sor Op.6, No.8 (page 8 in Tecla
101).
Segovia Study No.2 = Sor Op.35,
No.13 (page 68 in Tecla 101).
Segovia Study No.3 = Sor Op.6,
No.2 (page 2 in Tecla 101).
Segovia Study No.4 = Sor Op.6,
No.1 (page 1 in Tecla 101).
Segovia Study No.5 = Sor Op.35,
No.22 (page 77 in Tecla 101).
Segovia Study No.6 = Sor Op.35,
No.17 (page 72 in Tecla 101).
Segovia Study No.7 = Sor Op.31,
No.21 (page 53 in Tecla 101).
Segovia Study No.8 = Sor Op.31,
No.16 (page 47 in Tecla 101).
Segovia Study No.9 = Sor Op.31,
No.20 (page 52 in Tecla 101).
Segovia Study No.10 = Sor Op.31,
No.19 (page 50 in Tecla 101).
Segovia Study No.11 = Sor Op.6,
No.3 (page 2 in Tecla 101).
Segovia Study No.12 = Sor Op.6,
No.6 (page 5 in Tecla 101).
Segovia Study No.13 = Sor Op.6,
No.9 (page 8 in Tecla 101).
Segovia Study No.14 = Sor Op.6,
No.12 (page 14 in Tecla 101).
Segovia Study No.15 = Sor Op.35,
No.16 (page 70 in Tecla 101).
Segovia Study No.16 = Sor Op.29,
No.23 (page 30 in Tecla 101).
Segovia Study No.17 = Sor Op.6,
No.11 (page 12 in Tecla 101).
Segovia Study No.18 = Sor Op.29,
No.22 (page 28 in Tecla 101).
Segovia Study No.19 = Sor Op.29,
No.13 (page 16 in Tecla 101).
Segovia Study No.20 = Sor Op.29,
No.17 (page 22 in Tecla 101).
Here's the history. Andrés Segovia published his selection of twenty pieces by Sor, which he called "Twenty Studies", in the 1920s. He added new modern fingering which reflected the playing technique of his own day which was different from Sor's technique, especially in the right hand use of the "a" finger which Sor used very rarely but Segovia a great deal.
In fact only some of the twenty pieces are what Sor called studies, while others Sor called lessons or exercises. Segovia appears to have based his edition not on the original editions of Sor's music, but rather on a later selection of 24 pieces which had been chosen by Sor's student Napoléon Coste, and he added the new modern fingering.
The new Tecla/Hebe edition uses only Sor's own fingering and does not add any new fingering. Sor composed several of the studies specifically to give practice in his own technique and fingering.