@article{IJAMCS_2005__15_4_207755,
     author = {Stefen Hui and Stanis{\l}aw \.Zak},
     title = {Observer design for systems with unknown inputs},
     journal = {International Journal of Applied Mathematics and Computer Science},
     pages = {431},
     publisher = {mathdoc},
     volume = {15},
     number = {4},
     year = {2005},
     zbl = {1127.93018},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/item/IJAMCS_2005__15_4_207755/}
}