Memory Capacity References

Baddley, A. (1992), Working memory, Science, 255, 556-559.

Broadbent, D. E.  The magic number 7 after fifteen years.  In A. Kennedy
and A. wilkes (Eds.)  Studies in Long-Term Memeory.  London, Wiley, 1975.

Lindsey, P. H., & Norman, D. A. (1977). Human information processing.
New York: Academic Press.

Neisser, U. Cognitive Psychology.  Appleton-Century-Crofts, New York, 1967.

S. K. Card, T. P. Moran, and A. Newell. The psychology of human-computer 
interaction. Lawrence Erlbaum Associates, Hillsdale, NJ, 1983.