1. Arslanov, M.M.: Structural properties of the degrees below 0?. Dokl. Akad. Nauk SSSR, N.S.283, 270?273 (1985)
2. Cooper, S.B.: A splitting theorem for then-r.e. degrees (to appear)
3. Cooper, S.B., Harrington, L., Lachlan, A.H., Lempp, S., Soare, R.I.: A nondensity theorem for thed-r.e. degrees (in preparation)
4. Cooper, S.B., Lempp, S., Watson, P.R.: Weak density and cupping in thed-r.e. degrees. Isr. J. Math.67, 137?152 (1989)
5. Downey, R.:D-r.e. degrees and the nondiamond theorem. J. Lond. Math. Soc. (to appear)