Perhaps you should try some spelling variations:
dang van » hoang van, hang va
danh gia » dan gian
hieu van » hieu va, thien van, lieu va
va danh » va dinh, va dan, va hanh
van bac » van ban, van bao, van hac
sach ty » sach tu, sach thu, xach tay
su tien » su kien, su hien, tu tieng
nang ma » tang ma, sang ma, nang cao
xuc va » duc va, tuc va, luc va
gia su » gia suc, giao su, gia sa

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((sach ty) or (sach y)) ((nang ma) or (dang van)) hoi. hieu van bac xuc va danh gia su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((sach ty) OR (sach y)) ((nang ma) OR (dang van)) hoi. hieu van bac xuc va danh gia su tien.
• Adding a wildcard symbol may retrieve word variants: doc ((sach ty) or (sach y)) ((nang ma) or (dang van)) hoi. hieu van bac xuc va danh gia su tien*.