I recently attended a lecture on allelopathy by Elisabeth M. Gross the leading researcher on alleleopathy in Europe.
She's written a paper(one of many) named ' Alleleopathy of Aquatic Autotrophs'

Very interesting read..

it can be found in:

Critical reviews in Plant Sciences 22 (3&4):313-339 (2003)


or I can scan you a copy from work, if you haven't got access to the paper.