Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
thu sach » thuat sach, thuoc sach, thu hoach
va thanh » gia thanh, ban thanh, va tinh
tu sach » su sach, te sach, tu cach
va hanh » van hanh, va danh, ban hanh
su viet » so viet
hieu va » lieu va, hieu qua
lo nang » ho nang, ly nang, loai nang
va nam » van nam, ha nam, va nay
x hoi » xa hoi, o hoi, x ho
di su » doi su, ki su, da su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (thu sach)) lo nang x hoi. hieu va nam thuc ((va hanh) or (va thanh)) di su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) lo nang x hoi. hieu va nam thuc ((va hanh) OR (va thanh)) di su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) lo nang x hoi. hieu va nam thuc ((va hanh) or (va thanh)) di su viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) lo nang x hoi. hieu va nam thuc ((va hanh) or (va thanh)) di su viet*.