References for Size of the Universe
- S Clark, Towards the edge of the universe :A review of modern cosmology (Wiley, London, 1997).
- K Ferguson, Measuring the universe : The historical quest to quantify space (headline, London, 1999).
- J and M Gribbin, How far is up? (Icon Books, Cambridge, 2003.
- M Rowan-Robinson, The cosmological distance ladder (Freeman, San Francisco, 1985).