Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh dai » hanh tai, hanh dao, vanh dai
tham loc » tham nuoc, cham soc, tham hoa
va hanh » van hanh, va thanh, va danh
hau loc » huu loc, phau hoc
sach uu » sach luu, sach tu, sach xu
cao hoi » cau hoi, co hoi, cao hoc
sach ha » sach nha, sach han, sach xa
cua tre » cua te, cuu tre, cua triet

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 uu) or (sach ha)) nang cao hoi. hieu van ((tham loc) OR (hau loc)) va hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach uu) OR (sach ha)) nang cao hoi. hieu van ((tham loc) OR (hau loc)) va hanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach uu) or (sach ha)) nang cao hoi. hieu van ((tham loc) OR (hau loc)) va hanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach uu) or (sach ha)) nang cao hoi. hieu van ((tham loc) OR (hau loc)) va hanh dai cua tre*.