> [[petrov]]. "Vital Enegery, Spirits and Gods in Mari Folk Medicine". Folk Belief Today, Tartu 1995. ISBN 9985-851-11-0. Page 362f. > #nodoi > [pdf](a/petrov1995-vital.pdf) > #link ## Extract > The theory of the vital energy was possibly created as a result of interrelations among ancient Uralic peoples, Indo-Europeans and some other Eurasians. The term yu may be connected with Indo-European root yu (in Sanskrit ayu – life).