Sor’s variations on “Que ne suis-je la fougère” op. 26 were published in Paris in 1827, shortly after his return from Russia where they may have been composed.
You can hear these Variations on “Que ne suis-je la fougère” op. 26 played by Patrik Kleemola here.
This edition comes from the new 2020 second edition of Sor’s New Complete Works for Guitar edited by Brian Jeffery. The Introduction and Index to the entire series can be seen here on this site.