00360nam a2200121Ia 4500082002400000100001800024245008500042260002900127300002100156490005100177500000500228700000500233  a309.262015bW746.CT  aWilson, A. G.  aCatastrophe theory and bifurcation; applications to urban and regional systemsb  aLondonbCroom Helmc1981  axxi, 331p. Index  aCroom Helm series in Geography and Environment  a  a