Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vanh tai » van tai, hanh tai, anh tai
te sach » toc sach
su sach » so sach, vu sach
ty nang » ky nang, ty xang, ty hang
nang ma » tang ma, sang ma, nang cao
van cau » van dau, van hau, van chat
va vanh » va van, va danh, va hanh
ma hoi » mai hoi, xa hoi, ma hoa
cau tu » dau tu, cau truc
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: ((te sach) or (su sach)) ty nang ma hoi. hieu van cau tu va vanh tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (su sach)) ty nang ma hoi. hieu van cau tu va vanh tai va thiet.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (su sach)) ty nang ma hoi. hieu van cau tu va vanh tai va thiet*.