Perhaps you should try some spelling variations:
vu sach » vu bach, su sach, vu khach
ky lang » ky dang, ky tang, tay lang
hieu ke » hieu kem, chieu ke, hieu ky
tinh va » tich va, trinh van, trinh vat
cua tre » cua te, cuu tre, cua triet
ke cau » ket cau
luc va » tuc va, loc va
va cua » va chua, via cua, ca cua

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

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