George Barmpalias Andrew E. M. Lewis Mariya Ivanova Soskova Working with the <i>LR</i> Degrees. 89-99 2007 conf/tamc/2007 TAMC http://dx.doi.org/10.1007/978-3-540-72504-6_8 db/conf/tamc/tamc2007.html#BarmpaliasLS07