There are many books and articles onm tunnelling and as the subject is so varied I could not begin to list the books.
I suggest you buy the magazine Tunnels and Tunnelling International which has current news on tunnelling around the World and is pblished monthly. This magazine is published by Polygon Media (Tel +44 (0)20 8845 8545).
The best text book to get is now out of print but someone may be able to loan it to you. It is "The Art Of Tunnelling" by Karl Szechy (published by Balkema).