@article{JRAM_1980__320_152290,
     author = {Robert Varley and Robert Carlson},
     title = {Grassmannian subvarieties arising in the spectral theory of ordinary differential operators.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {32--43},
     publisher = {mathdoc},
     volume = {320},
     year = {1980},
     zbl = {0454.34017},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1980__320_152290/}
}