Four of the ten chapters of Immortality or Resurrection? by Samuele Bacchiocchi.
The Rich Man and Lazarus: An Intermediate State? Luke 16:19-31 by E.W. Bullinger, DD.
What Happens When We Die? by Anthony Buzzard
Duration and Nature of Future Punishment by Henry Constable.
Hades: or the Intermediate State of Man by Henry Constable.
Immortality of the Soul or Resurrection of the Dead? by Oscar Cullmann (The Internet Edition Completed January 2002)
The Doctrine of Immortality in the Early Church by Dr. John H. Roller.