Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
lang xa » lang ha, dang xay, lang van
hieu ve » hieu van
cua tre » cua te, cuu tre, cua triet
sach o » sach lo, sac o, sach y
o lang » hoa lang, hoi lang
va cua » va chua, via cua, ca cua

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 o lang xa hoi. ((hieu ve) OR (hieu va)) ((cham soc) or (nham thuc)) va danh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach o lang xa hoi. ((hieu ve) OR (hieu va)) ((cham soc) OR (nham thuc)) va danh va cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach o lang xa hoi. ((hieu ve) OR (hieu va)) ((cham soc) or (nham thuc)) va danh va cua tre*".