Hi, I have got Ramesh Singh 6th edition and Laxmikanth 4th edition with me and studied both once for prelims 2016. Couldn't qualify this year though so preparing again for 2017. So now Ramesh Singh has released its 8th edition and Laxmikanth is soon to release his 5th edition. Is it necessary to purchase the newer editions for 2017 or will studying from the older editions do? Those who have got the newer edition of Ramesh Singh and had a look on the older editions too can you please tell if there are any relevant additions to the content? Thank you.