All engineering ebook(pdf)

AIRCEL Dial *1# or *234*4# or *888# or
*122*131# or *131#
Tata docomo Dial *1# or *580# or *124#
Airtel Dial *140*175# or *140*1600# or *121*9#
or *282# or *141*123#
Reliance Dial *1# or *111#
Uninor Dial *555# or *1# or *444#
Vodafone Dial *555# or *555*0# or *111*2# or
*777*0# or *131*0#
BSNL Dial *1# or *99# or *222#
Idea Dial *131*1# or *789# or *100# or *1# or
*147# or *131#
Videocon Dial *1#
Virgin Dial *1#
Loop Dial *222# or *1# or *001#
MTNL Dial *8888#
Smart Dial *1# or *111*2#
BPL Dial *222# or *1# or *001#