Ditchev A. SOME RESULTS ON THE UPPER-SEMILATTICE OF R.E. $m$-DEGREES INSIDE A SINGLE R.E. $tt$-DEGREE. Ann. Sofia Univ. Fac. Math. and Inf. [Internet]. 2004 Dec. 12 [cited 2024 Nov. 24];96:23-34. Available from: https://ftl5.uni-sofia.bg./index.php/fmi/article/view/158