Perhaps you should try some spelling variations:
dang xay » dang van, van xay
hanh dai » hanh tai, hanh dao, vanh dai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
va cam » va cham, va cao, va cai
luc va » duc va, tuc va, loc va
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 ((nang x) or (dang xay)) hoi. hieu ((va cam) OR (va cac)) luc va hanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang x) OR (dang xay)) hoi. hieu ((va cam) OR (va cac)) luc va hanh dai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang x) or (dang xay)) hoi. hieu ((va cam) OR (va cac)) luc va hanh dai cua te*".