The list I have provided is based on general knowledge of European genetics, historical migration patterns, and geographic proximity. However, it is not derived from a specific study or source. Instead, it reflects broader trends observed in population genetics. More rigorous and precise comparisons of genetic similarity between populations require scientific studies in population genetics, such as those using data from the Human Genome Project, the 1000 Genomes Project, or other large-scale genetic databases. These studies typically use data from genetic markers such as Single Nucleotide Polymorphisms (SNPs) to measure genetic distance between populations.