@article{ caines_hierarchical_1998, title = {Hierarchical hybrid control systems: A lattice theoretic formulation}, volume = {43}, shorttitle = {Hierarchical hybrid control systems}, url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=664153}, number = {4}, urldate = {2013-09-24}, journal = {Automatic Control, {IEEE} Transactions on}, author = {Caines, Peter E. and Wei, Yuan-Jun}, year = {1998}, pages = {501–508} }