This is an identical listing for Vladigerov's major suite of piano pieces exploring Bulgarian folk idiom. It is marked by its virtuosic demands and evocative, late-Romantic harmonic language.
Focus on controlled voicing within the dense harmonic clusters to avoid muddy pedaling.
Comparable difficulty and character — good candidates for what to learn next.
Bulgarischen Suite (Op.21) is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 10.
You should be comfortable at Henle level 6 — meaning you can already play level 5–6 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
A typical performance of Bulgarischen Suite (Op.21) lasts about 15 minutes.
Bulgarischen Suite (Op.21) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include Bulgarische Suite by Pancho Haralanov Vladigerov, Boléro by Maurice Ravel, Prelude in C-sharp minor, No. 2 by Sergei Rachmaninoff — see the full similar-pieces list on this page.