As a result, trying to craft precisely punitive trade measures aimed at particular nations, or even companies, is an exceedingly difficult task. (blog.politics.ox.ac.uk)
Hudec, R.E. (1996), GATT Legal Restraints on the Use of Trade Measures against Foreign Environmental Practices, in J. Bhagwati and R.E. Hudec (eds.) (mpra.ub.uni-muenchen.de)
Now Ontario and Quebec officials are not ruling out taking retaliatory trade measures against New York. (nystateofpolitics.com)