Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
ve cham » va cham, ve chat, vu cham
tuan vi » quan vi, luan vi, quans vi
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
ve cam » ve cac, va cam, ve cai
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky dang xay hoi. hieu ((ve cam) OR (ve cham)) ((duc va) or (duc tan)) tuan vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang xay hoi. hieu ((ve cam) OR (ve cham)) ((duc va) OR (duc tan)) tuan vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang xay hoi. hieu ((ve cam) OR (ve cham)) ((duc va) or (duc tan)) tuan vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xay hoi. hieu ((ve cam) OR (ve cham)) ((duc va) or (duc tan)) tuan vi cua tre*.