For those who's basics are covered but they feel they need to build a perspective and connect the dots for mains, you may refer to these free mains advanced discussions as well. All the best. Hope it helps! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-f19gb78ob6o.html
Many methods are there reg.studies of any subject perticular economics which is directly proportional to the economy.Reed any book bt.Basics shud b clear nd keep updating with current affairs in my view nd b honest and sincere iny view in brief Inspiring vdo.in nutshell.Thanks