Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
dang xay » dang van, van xay
su sach » so sach, vu sach
cua tre » cuu tre, cua triet, dua tren
tuc van » thuc van, truc van, tuc va
cam tuc » cam xuc, cam tu, nam thuc
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
lang xa » lang ha, lang van
va cam » va cham, va cac, va cao
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: su sach ky ((lang xa) or (dang xay)) hoi. hieu va cam tuc van hanh vi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((lang xa) OR (dang xay)) hoi. hieu va cam tuc van hanh vi ((cua tre) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: su sach ky ((lang xa) or (dang xay)) hoi. hieu va cam tuc van hanh vi ((cua tre) or (cua te))*.