i realised that the bookshelf doesnt need to stick out too much from the wall... im just wasting the material!! so i reduced the depth of the bookshelf from 300mm to 200mm... which is still able to hold larger books like magazines =)
and by mounting onto the wall with screws !! hm... i know i didnt show that in my previous picture... cos i need to work out the size of the screw that holds the bookshelf... and im still deciding on which type of screw to use...