@article{CM_1983__49_1_75_0, author = {Dekker, J. C. E.}, title = {Isols and balanced block designs with $\lambda = 1$}, journal = {Compositio Mathematica}, pages = {75--93}, publisher = {Martinus Nijhoff Publishers}, volume = {49}, number = {1}, year = {1983}, zbl = {0524.05012}, language = {en}, url = {http://archive.numdam.org/item/CM_1983__49_1_75_0/} }