Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
qua dau » qua da, qua bau, qua dan
dau cua » dai cua, day cua, cau cua
cua van » cua ban, cua vat, cua dan
vi cua » vai cua, di cua
cua te » cua tu

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 hoach)) y ((nang xa) OR (lang xa)) hoi. hieu qua dau cua van hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu hoach)) y ((nang xa) OR (lang xa)) hoi. hieu qua dau cua van hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu hoach)) y ((nang xa) OR (lang xa)) hoi. hieu qua dau cua van hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu hoach)) y ((nang xa) OR (lang xa)) hoi. hieu qua dau cua van hanh vi cua te*.