Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
lam duoc » nam duoc, luat duoc, lam thuoc
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
duoc va » nuoc va, duc va, duoc ma
van lam » van nam
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, lang van
nang xa » nang x, nang ma, mang xa
tai va » thai va, mai va, tri va
thiet* » thieu*

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 ky ((nang xa) or (((lang xa) OR (dang xay)))) hoi. hieu van lam duoc va hanh tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (((lang xa) OR (dang xay)))) hoi. hieu van lam duoc va hanh tai va thiet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (((lang xa) OR (dang xay)))) hoi. hieu van lam duoc va hanh tai va thiet*".