Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vu khach » vu khanh, vu khac, vay khach
truc va » thuc va, trung va
hai cua » thai cua, dai cua, hoi cua
dao hai » dao thai, dai hai, do hai
su sach » so sach, vu sach
van cau » van dau, van hau, van chat
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (vu khach)) ky nang ma hoi. hieu van cau ((truc va) OR (thuc vat)) dao hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu khach)) ky nang ma hoi. hieu van cau ((truc va) OR (thuc vat)) dao hai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu khach)) ky nang ma hoi. hieu van cau ((truc va) OR (thuc vat)) dao hai cua te".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu khach)) ky nang ma hoi. hieu van cau ((truc va) OR (thuc vat)) dao hai cua te*.