Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
sach thi » sach thu, sach tai, sach thieu
thi hanh » thi thanh
hanh lai » hanh lam, hanh tai, thanh lap
thuc day » thuc dan, thuc vat
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
hanh xa » hanh va, hanh ma, hanh xu
hieu ve » hieu va
tuc va » thuc va, truc va, tuc xa
lai va » loai va, mai va, dai va

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 thi hanh xa hoi. ((hieu ve) OR (hieu van)) cam ((tuc va) or (thuc day)) hanh lai va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thi hanh xa hoi. ((hieu ve) OR (hieu van)) cam ((tuc va) OR (thuc day)) hanh lai va trien*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thi hanh xa hoi. ((hieu ve) OR (hieu van)) cam ((tuc va) or (thuc day)) hanh lai va trien*".