Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
ban danh » ban doanh, ban hanh, ban dan
danh vai » danh sai, danh va, doanh van
ky lang » ky dang, ky tang, tay lang
hieu ve » hieu va, hieu van
cau cua » cau qua, ca cua, cu cua
cua tre » cua te, cuu tre, cua triet
su viet » so viet
ve cau » ke cau, va cau, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ky lang) OR (ky nang)) xa hoi. hieu ve cau cua ban danh vai ((cua tre) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ky lang) OR (ky nang)) xa hoi. hieu ve cau cua ban danh vai ((cua tre) OR (su viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ky lang) OR (ky nang)) xa hoi. hieu ve cau cua ban danh vai ((cua tre) or (su viet))".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky lang) OR (ky nang)) xa hoi. hieu ve cau cua ban danh vai ((cua tre) or (su viet))*.