Is it possible to connect a second external monitor to Macbook Air Mid 2013?

I have one external monitor connected to Mini DisplayPort to DVI adapter on MacBook Air Mid 2003. Now I have a spare monitor with DVI, HDMI and VGA input amd I'd like to add that as a second external display. Is it possible to connect another external monitor to a USB to HDMI adapter? I guess that would be the cheapest option if it worked? Then there's also Mini DisPlayPort with dual-link DVI. Is that supported by Air Mid 2013? This is all very confusing and different sites seem to give different and conflicting info.