Business rules and Triggers

I am doing some research for a projetc about the implementation of Business Rules in Triggers.

I am looking for documentation ( Technical report, paper, ....even commercial paper...) about the different systems existing ( by Oracle, Sybase, Informix.....)

The ideal paper would be that is doing a comparison between the main systems existing ....

If you have any of these paper or if you know where I could find any , please let me know

P.S. : I will be happy with any paper in English or French

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Laurent PHELEP                                      		 /\
Third Year Student in Computer Science                		 \/
University of Exeter                                  	       <>  <>
Email : L.Phelep_at_ex.ac.uk     				         /\
http://www.dcs.exeter.ac.uk/ug/cs95/lp/             		/  \
                                                   	       /    \
Kenavo                                           	      / /\/\ \