Jin-Heum Paek Tae-Eog Lee Optimal scheduling of dual-armed cluster tools without swap restriction. 103-108 2008 CASE https://doi.org/10.1109/COASE.2008.4626564 https://www.wikidata.org/entity/Q58199780 conf/case/2008 db/conf/case/case2008.html#PaekL08