Fellow Part C Cadets:
Here are some additional material for the Land Spec Course which may be useful:
1. Notes from the Refresher Course (have to login into MSHS google account)
2. JSS NCC Group
There are some useful information about NCC and Trainfire here
3. GVSS NCC Handbook
Other information that is for general reading
Also do check the NCC information on the NCC official website.
Do share if you have any other sources that will be helpful for everyone to use.