Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
nang mai » nang ma, lang mai, nang cai
nang tai » hang tai, tang tai, sang tai
tu sach » thu sach, su sach, te sach
cua tuc » cua duc, cua thuoc, luat tuc
hanh di » hanh vi, hanh de, hang di
cao suc » cao su, cao duc
suc van » su van, duc van, luc van
va cao » va cac, va co, va dao
cua tu » cua su, cua cu, cua te

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 y ((nang mai) or (nang tai)) hoi. lieu va cao suc van hanh di ((cua tuc) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang mai) OR (nang tai)) hoi. lieu va cao suc van hanh di ((cua tuc) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang mai) or (nang tai)) hoi. lieu va cao suc van hanh di ((cua tuc) OR (cua tu))".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang mai) or (nang tai)) hoi. lieu va cao suc van hanh di ((cua tuc) OR (cua tu))*.