L1 http://www.3dcadservicesindia.com/mechanical/
L2 http://wonderfulengineering.com/what-is-materials-engineering/
L3 http://wordpress.mrreid.org/tag/light/
L4 http://www.thomasnet.com/articles/custom-manufacturing-fabricating/how-casting-works
L5 http://www.advanceindustriesgroup.com/MetalForming.html
L6 http://www.chinarollformingmachines.com/incremental-bulk-metal-roll-forming-machine.html
L7 http://www.smartclima.com/steel-sheet-stamping
L8 http://www.ncsmi.com/index.html
L9 http://www.fabricatingandmetalworking.com/2013/01/2013-state-of-the-industryrajas-sukthankar-siemens-industry/
L10 http://thecolfaxproject.com/?portfolio=products
L11 http://wardensinc.com/