@article{JRAM_1989__401_153169,
     author = {Eugene Gutkin and Russell Johnson},
     title = {Intersection theory for linear eigenvalue problems.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {1--24},
     publisher = {mathdoc},
     volume = {401},
     year = {1989},
     zbl = {0676.35072},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1989__401_153169/}
}