The fact so similar customs in the Balkans are known by two different names the differences are considered not to be from the same time period and ethnic groups. It is usually considered they have a mythological and etymological Slavic origin related to Slavic thunder-god Perun, and became widespread in the Southeastern Europe with the Slavic migrations to the Balkans (6th-10th century). According to the Slavic theory, it is a (Balto-)Slavic heritage of Proto-Indo-European origin related to Slavic thunder-god Perun. It has parallels in ritual prayers for bringing rain in times of drought dedicated to rain-thunder deity Parjanya recorded in the Vedas and Baltic thunder-god Perkūnas, cognates alongside Perun of Proto-Indo-European weather-god Perkwunos. The same ritual in an early medieval Ruthenian manuscript is related to East Slavic deity Pereplut. According to Jakobson, Novgorod Chronicle ("dožd prapruden") and Pskov Chronicle ("dožd praprudoju neiskazaemo silen") could have "East Slavic trace of Peperuda calling forth the rain", and West Slavic god Pripegala reminds of Preperuga/Prepeluga variation and connection with Perun. Serbo-Croatian archaic variant Prporuša and verb prporiti se ("to fight") also have parallels in Old Russian ("porъprjutъsja"). The name Dodola is cognate with the Lithuanian Dundulis, a word for "thunder" and another name of the Baltic thunder-god Perkūnas. It is also distantly related to Greek Dodona and Daedala. Bulgarian variant Didjulja is similar to alleged Polish goddess Dzidzilela, and Polish language also has verb dudnić ("to thunder"). According to another interpretation the name Perperuna can be identified as the reduplicated feminine derivative of the name of the male god Perun (per-perun-a), being his female consort, wife and goddess of rain Perperuna Dodola, which parallels the Old Norse couple Fjörgyn–Fjörgynn and the Lithuanian Perkūnas–Perkūnija. Perun's battle against Veles because of Perperuna/Dodola's kidnapping has paralles in Zeus saving of Persephone after Hades carried her underground causing big drought on Earth, also seen in the similarity of the names Perperuna and Persephone. Recent research criticize invention of a Slavic female goddess. Another explanation for the variations of the name Dodola is relation to the Slavic spring goddess (Dido-)Lada/Lado/Lela, some scholars relate Dodole with pagan custom and songs of Lade (Ladarice) in Hrvatsko Zagorje (so-called "Ladarice Dodolske"), and in Žumberak-Križevci for the Preperuša custom was also used term Ladekarice. Similar customs have been observed in the Balkans, Caucasus, Middle East, and North Africa. William Shedden-Ralston noted that Jacob Grimm thought Perperuna/Dodola were "originally identical with the Bavarian