@article{CMH_1990__65_3_140197,
     author = {M. Strake and R.J. Spatzier},
     title = {Some examples of higher rank manifolds of nonnegative curvature.},
     journal = {Commentarii mathematici Helvetici},
     pages = {299--317},
     publisher = {mathdoc},
     volume = {65},
     number = {3},
     year = {1990},
     zbl = {0713.53029},
     url = {http://geodesic.mathdoc.fr/item/CMH_1990__65_3_140197/}
}