@article{10_4064_fm_81_4_279_290,
     author = {Ronald Jensen and H\r{a}vard Johnsbr\r{a}ten},
     title = {A new construction of non-constructible ${\ensuremath{\Delta}^1}_3$ subset of \ensuremath{\omega}},
     journal = {Fundamenta Mathematicae},
     pages = {279--290},
     publisher = {mathdoc},
     volume = {81},
     number = {4},
     year = {1973},
     doi = {10.4064/fm-81-4-279-290},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-81-4-279-290/}
}