@article{CM_1990__76_3_367_0,
     author = {Smith, Roy and Varley, Robert},
     title = {Deformations of theta divisors and the rank $4$ quadrics problem},
     journal = {Compositio Mathematica},
     pages = {367--398},
     publisher = {Kluwer Academic Publishers},
     volume = {76},
     number = {3},
     year = {1990},
     mrnumber = {1080008},
     zbl = {0745.14012},
     language = {en},
     url = {http://www.numdam.org/item/CM_1990__76_3_367_0/}
}