His doctorate thesis "Mbi shtresëzimet në gjuhën shqipe" was written under the guide of Professor Matteo Bartoli.
Resuli returned in Albania in the 1930s and taught Albanian language in Elbasan Normal School, now Aleksandër Xhuvani University, as well as in Shkodër and Tirana.
In 1954 he published in Turin the magazine Shpirti Shqiptar (Albanian Soul).
His study on the Missal (Meshari) of Gjon Buzuku (Città del Vaticano, 1958) is the first of its genre in the history of Albanology, whereas his work Grammatica della lingua albanese (Bologna, 1985) is considered an important approach in teaching the Albanian language to foreigner speakers.
[4][5] He was of the opinion that the standard Albanian language would naturally lean toward the dialects of Central Albania.