The three haplogroups most strongly associated with Albanian people are E-V13, R1b and J-M172. E-V13 and J2-M12 (the parent clade of J-M172) are considered by Cruciani et al to both indicate a particular "range expansion in the Bronze Age of southeastern Europe", having experienced considerable "in situ" population growth after having being introduced in an earlier period with the spread of the Neolithic into Europe. R1b, meanwhile, has been associated with the spread of Indo-European languages in Europe. Within the Balkans, all three have a local peak in Kosovo, and are overall more common among Albanians, Greeks and Vlachs than South Slavs (albeit with some representation among Macedonians and Bulgarians). R1b has much higher frequencies in areas of Europe further to the West, while E1b1b and J2 are widespread at lower frequencies throughout Europe, and also have very large frequencies among Greeks, Italians, Macedonians and Bulgarians.