Generally NET level book is not required,. But I will suggest u to complete the syllabus topic wise. For example: if u want to complete the topic - plants as sources for spices - u should not purchase the book of economic botany for this topic, instate u should go to any university library find botany stall, take 2 to 3 economic botany book and then take any five plants that produce spices and prepare notes accordingly. Once u have the notes of plant as source for spices, this note will be the great source for writing answer in UPSC mains, because it is prepared from 2 to 3 reference books. Then u should repeat this method for every topic. In this way u will complete all syllabus and will have all sorts of notes at the end. Make sure to add notes from our video lectures as well because these lectures are also prepared using good reference books...
