Sh:321

Bib entry
@article{Sh:321,
 author = {Judah, Haim I. and Shelah, Saharon},
 title = {{$\Delta^1_2$-sets of reals}},
 journal = {Ann. Pure Appl. Logic},
 fjournal = {Annals of Pure and Applied Logic},
 volume = {42},
 number = {3},
 year = {1989},
 pages = {207--223},
 issn = {0168-0072},
 doi = {10.1016/0168-0072(89)90016-X},
 mrclass = {03E15},
 mrnumber = {998607},
 mrreviewer = {David E. Marker},
 doi = {10.1016/0168-0072(89)90016-X}
}