Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
chua tre » chua tri, chua trieu, cho tre
su sach » so sach, vu sach
va dinh » van dinh, va kinh, va tinh
va danh » va dan, va hanh, dia danh
va nham » va cham, va tham, va nha
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
sach o » sach lo, sac o, sach y
o lang » hoa lang, hoi lang

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