Perhaps you should try some spelling variations:
nhung cau » chung cu, nhung bai, nhu cau
van hanh » van thanh, ban hanh, van anh
sach thu » sach thue, sach thieu, sach tham
duc van » duc va, duc tan, duc manh
hanh va » hang va, hanh vi
qua cai » qua hai, qua cac, qua ca
cai duc » cao duc, mai duc, hoai duc
sach ty » sach y, sach tu, xach tay
cua tu » cua tuc, cua su, cua cu

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) OR (sach thu)) nhung cau hoi. hieu qua cai duc van hanh va ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach ty) OR (sach thu)) nhung cau hoi. hieu qua cai duc van hanh va ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sach ty) OR (sach thu)) nhung cau hoi. hieu qua cai duc van hanh va ((cua te) or (cua tu))".
• Adding a wildcard symbol may retrieve word variants: thuat ((sach ty) OR (sach thu)) nhung cau hoi. hieu qua cai duc van hanh va ((cua te) or (cua tu))*.