Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach lo » sach dao, sach doi, sach hoi
lo nang » ho nang, ly nang, loai nang
hieu va » lieu va, hieu qua
va hanh » va thanh, va danh, ban hanh
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 lo nang x hoi. hieu va nam thuc ((((va hanh) OR (van hanh))) or (may tinh)) di su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach lo nang x hoi. hieu va nam thuc ((((va hanh) OR (van hanh))) OR (may tinh)) di su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach lo nang x hoi. hieu va nam thuc ((((va hanh) OR (van hanh))) or (may tinh)) di su triet*".