http://grasshopper.com/
http://www.airtel.in/aes/home/Voice/Toll+Free+Services
http://dir.indiamart.com/impcat/toll-free-number-service.html
http://www.justdial.com/Delhi-NCR/Toll-Free-Service-Providers/ct-1000671044
http://www.avoxi.com/international-toll-free-number-service-itfs/
https://www.knowlarity.com/sr/cms/pricing/
http://www.airtel.in/aes/home/Voice/Toll+Free+Services
http://dir.indiamart.com/impcat/toll-free-number-service.html
http://www.justdial.com/Delhi-NCR/Toll-Free-Service-Providers/ct-1000671044
http://www.avoxi.com/international-toll-free-number-service-itfs/
https://www.knowlarity.com/sr/cms/pricing/