Perhaps you should try some spelling variations:
thi hang » thi hanh, thi nang, thi thanh
thi hong » thi cong, thi phuong, thi hanh
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
dao su » dao suu, dan su, da su
va am » va lam, va cam

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 hang) OR (thi hong)) xa hoi. hieu va am thuc va hanh ((dao su) or (cao su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((thi hang) OR (thi hong)) xa hoi. hieu va am thuc va hanh ((dao su) OR (cao su)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((thi hang) OR (thi hong)) xa hoi. hieu va am thuc va hanh ((dao su) or (cao su)) triet".
• Adding a wildcard symbol may retrieve word variants: su sach ((thi hang) OR (thi hong)) xa hoi. hieu va am thuc va hanh ((dao su) or (cao su)) triet*.