S. Chan; A. Wong; E. Lam (2008), "Initialization for robust inverse synthesis of phase-shifting masks in optical projection lithography", Optics Express, 16 (19): 14746–14760, Bibcode:2008OExpr..1614746C, doi:10.1364/OE.16.014746, PMID 18795012 http://www.opticsinfobase.org/abstract.cfm?uri=oe-16-19-14746
Inverse Lithography Technology (ILT) https://semiengineering.com/knowledge_centers/manufacturing/lithography/photomask/inverse-lithography-technology-ilt/
S. Chan; A. Wong; E. Lam (2008), "Initialization for robust inverse synthesis of phase-shifting masks in optical projection lithography", Optics Express, 16 (19): 14746–14760, Bibcode:2008OExpr..1614746C, doi:10.1364/OE.16.014746, PMID 18795012 http://www.opticsinfobase.org/abstract.cfm?uri=oe-16-19-14746