Carleton Coffrin Hassan L. Hijazi Karsten Lehmann Pascal Van Hentenryck Primal and dual bounds for Optimal Transmission Switching. 1-8 2014 PSCC https://doi.org/10.1109/PSCC.2014.7038446 conf/pscc/2014 db/conf/pscc/pscc2014.html#CoffrinHLH14