Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cham cuc » cham cuu, pham cuc, pham chuc
ban hanh » ban hang
cac khoi » cac thoi, cac khoan, cach thoi
doi cua » dai cua, hoi cua
cuc ban » cua ban, cac ban, cuu ban
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky lang) OR (ky tang)) cac khoi. hieu ve cham cuc ban hanh ((vi cua) OR (doi cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ky lang) OR (ky tang)) cac khoi. hieu ve cham cuc ban hanh ((vi cua) or (doi cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky lang) OR (ky tang)) cac khoi. hieu ve cham cuc ban hanh ((vi cua) or (doi cua)) tre*.