@article{PismaZhETF.83.3, title = { Composite dark matter from 4-th generation}, author = {Khlopov, M. Yu.}, journal = {πΙΣΨΝΑ Χ φότζ}, volume = {83}, issue = {1}, pages = {3}, year = {2006}, doi = {}, url = {http://jetpletters.ru/ps/0/article_16033.shtml}, }