Perhaps you should try some spelling variations:
dang xay » dang van, van xay
cham sac » cham soc, pham sach, cap sac
van hanh » van thanh, ban hanh, van anh
vu sach » vu bach, su sach, vu khach
lang xa » lang ha, lang van
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
sac van » cac van, san van, sat van
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach y ((lang xa) OR (dang xay)) hoi. hieu vu cham sac van hanh di cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach y ((lang xa) OR (dang xay)) hoi. hieu vu cham sac van hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach y ((lang xa) OR (dang xay)) hoi. hieu vu cham sac van hanh di cua tre*.