@article{10_1017_S0017089502020062,
     author = {Crabb, M. J. and Duncan, J. and McGregor, C. M.},
     title = {The {Extremal} {Algebra} on {Two} {Hermitians} {With} {Square} 1},
     journal = {Glasgow mathematical journal},
     pages = {255--260},
     year = {2002},
     volume = {44},
     number = {2},
     doi = {10.1017/S0017089502020062},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089502020062/}
}