@article{JOLT_2004_14_2_a5,
     author = {D. D. Pervouchine},
     title = {Hierarchy of {Closures} of {Matrix} {Pencils<!--} {Anfang} {Autor} -->},
     journal = {Journal of Lie Theory},
     pages = {443--479},
     year = {2004},
     volume = {14},
     number = {2},
     doi = {10.5802/jolt.345},
     zbl = {1061.15012},
     url = {https://jolt.centre-mersenne.org/articles/10.5802/jolt.345/}
}