@article{CMH_1991__66_4_140251,
     author = {H. Karcher and H. Rosenberg and D. Hoffman},
     title = {Embedde minimal annuli in {R3} bounded by a pair of straight lines.},
     journal = {Commentarii mathematici Helvetici},
     pages = {599--617},
     publisher = {mathdoc},
     volume = {66},
     number = {4},
     year = {1991},
     zbl = {0765.53004},
     url = {http://geodesic.mathdoc.fr/item/CMH_1991__66_4_140251/}
}