Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
van hanh » van thanh, ban hanh, van anh
dang xay » dang van, van xay
phat duc » pham duc, phan duc, phan duoc
hieu va » lieu va, hieu qua
dang xa » lang xa, dang ha, dang va
cua tre » cua te, cuu tre, cua triet
duc van » duc va, duc tan, duc manh
su sai » su tai, su hai, su dai
sai ky » sac ky
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: su sai ky ((dang xa) OR (dang xay)) hoi. hieu va phat duc van hanh thai ((cua tre) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky ((dang xa) OR (dang xay)) hoi. hieu va phat duc van hanh thai ((cua tre) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sai ky ((dang xa) OR (dang xay)) hoi. hieu va phat duc van hanh thai ((cua tre) or (cua tu))".
• Adding a wildcard symbol may retrieve word variants: su sai ky ((dang xa) OR (dang xay)) hoi. hieu va phat duc van hanh thai ((cua tre) or (cua tu))*.