References

1. Skinner, BF (1953) Science and Human Behaviour, Macmillan: New York.

2. Olds, J (1956) Pleasure Centres in the Brain In: Coopersmith (ed.) Frontiers of Psychological Research. W H Freeman: San Francisco, pp 54-59.

3. Bozarth, MA (1991) The mesolimbic dopamine system as a mood reward system. In: Willner, P & Scheel-Kruger , K (eds.) The Mesolimbic Reward Systems. John Wiley & Sons Ltd.: London. pp301-330.

4. Meyer, VR (2001) Why is it a pleasure to drink coffee?Analytical Chemistry 73, 659.

5. Stone, AA, Reed, BR & Neale, JM (1987) Changes in Daily Event frequency precede episodes of physical symptoms. Journal of Human Stress, 13, 70-74.

6. Baron, RS, Cutrona, CE, Hicklin, D, Russel, DW & Lubaroff, DA (1990) Social support and immune functions among spouses of cancer patients. Journal of Personality and Social Psychology, 59, 344-352.

7. Frankenhauser, M (1986) A psychobiological framework for research on human stress and coping. In: Appley MH & Trumbell, R (eds.) Dynamics of Stress, Plenum Press, New York, pp 101-116.

8. Lieberman, HR (1992). Caffeine. In: Smith, AP & Jones, D (eds.) Handbook of Human Performance. Vol. 2. Academic Press: London, pp 49-72.

9. Warburton, DM (1995) The effects of caffeine on cognition and mood without caffeine abstinence. Psychopharmacology, 119, 66-70.

10. Shin, DC & Johnson, DM (1978) Avowed happiness as an overall assessment of the quality of life. Social Indicators Research, 5, 475-492.

For further information, visit Links