@article{10_4064_sm184_1_4,
     author = {Daniel Freeman},
     title = {Weakly null sequences with upper estimates},
     journal = {Studia Mathematica},
     pages = {79--102},
     publisher = {mathdoc},
     volume = {184},
     number = {1},
     year = {2008},
     doi = {10.4064/sm184-1-4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm184-1-4/}
}