@article{10_4064_fm_135_1_1_4,
     author = {Stephen Watson and Zhou Hao-Xuan},
     title = {Caliber ($\ensuremath{\omega}_1$, \ensuremath{\omega}) is not productive},
     journal = {Fundamenta Mathematicae},
     pages = {1--4},
     publisher = {mathdoc},
     volume = {135},
     number = {1},
     year = {1990},
     doi = {10.4064/fm-135-1-1-4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-135-1-1-4/}
}