@article{TM_1970_111_a11,
     author = {S. M. Ermakov},
     title = {The optimal unbiased plans of regression experiments},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {252--257},
     year = {1970},
     volume = {111},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1970_111_a11/}
}