Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
van hanh » van thanh, ban hanh, van anh
hanh ki » hanh vi, hanh ky, hanh kien
xuc van » duc van, luc van, vuc van
van lam » van nam
van cam » van nam, van cau, van dam
sach ty » sach y, sach tu, sach thu
lang xa » lang ha, dang xay, lang van
su viet » so viet
ki su » ky su

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ty ((lang xa) or (nang x)) hoi. thien ((van cam) OR (van lam)) xuc van hanh ki su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ty ((lang xa) OR (nang x)) hoi. thien ((van cam) OR (van lam)) xuc van hanh ki su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ty ((lang xa) or (nang x)) hoi. thien ((van cam) OR (van lam)) xuc van hanh ki su viet".
• Adding a wildcard symbol may retrieve word variants: thuat sach ty ((lang xa) or (nang x)) hoi. thien ((van cam) OR (van lam)) xuc van hanh ki su viet*.