Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vu khach » vu khac, vay khach, cua khach
danh vai » danh sai, danh va, doanh van
vu khanh » vu thanh, van khanh, duy khanh
su sach » so sach, vu sach
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
truc va » thuc va, thuc vat, trung va
cua tre » cua te, cuu tre, cua triet
van cau » van dau, van hau, van chat
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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) OR (vu khanh)))) ky nang ma hoi. hieu van cau truc va danh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (((vu khach) OR (vu khanh)))) ky nang ma hoi. hieu van cau truc va danh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (((vu khach) OR (vu khanh)))) ky nang ma hoi. hieu van cau truc va danh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (((vu khach) OR (vu khanh)))) ky nang ma hoi. hieu van cau truc va danh vai cua tre*.