@article{MET_1994__41_5_176499,
     author = {Joachim Kunert},
     title = {Optimality of {Block} {Designs} with {Variable} {Block} {Sizes} and {Random} {Block} {Effects.}},
     journal = {Metrika},
     pages = {71--81},
     year = {1994},
     volume = {41},
     number = {5},
     zbl = {0802.62067},
     url = {http://geodesic.mathdoc.fr/item/MET_1994__41_5_176499/}
}