Perhaps you should try some spelling variations:
nhan tai » hang tai, van tai, toan tai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
xuc va » duc va, tuc va, luc va
loc va » hoc va, luc va
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: su sach ky ((nang xa) or (lang xa)) hoi. hieu ve cham ((xuc va) or (loc va)) nhan tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (lang xa)) hoi. hieu ve cham ((xuc va) OR (loc va)) nhan tai va thiet.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (lang xa)) hoi. hieu ve cham ((xuc va) or (loc va)) nhan tai va thiet*.