Renato Fernandes Hentschke Guilherme Flach Felipe Pinto Ricardo Reis Quadratic placement for 3d circuits using z-cell shifting, 3d iterative refinement and simulated annealing. 220-225 2006 conf/sbcci/2006 SBCCI http://doi.acm.org/10.1145/1150343.1150399 db/conf/sbcci/sbcci2006.html#HentschkeFPR06