Hamster Behaviour in Different Cages
In 2007 K. Fischer, S. Gebhardt and A. Steiger did a study on the behaviours of Syrian Hamsters kept in different-sized cages, you can find their findings here
Behaviour In Different Bedding Depths
In 2005 A. Hauzenberger, S. Gebhardt and A. Steiger did a study on the influence of bedding depth on behaviour in Syrian Hamsters. Find their findings here
Wheel Choice Study
In 2005 S. Reebs and P. St-Onge did a study on the preference of different wheel styles and sizes in Syrian hamsters. You can find their findings here