Perhaps you should try some spelling variations:
nang dai » nang dau, nang tai, lang dai
hang hai » hoang hai, hang tai, thanh hai
xang dau » hang dau
so sach » so sanh, bo sach, co sach
luu van » cuu van, luan van, luu hanh
hai cua » thai cua, dai cua, hoi cua
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
luc van » luoc van, duc van, luc va
ve cam » ve cham, ve cac, va cam
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: so sach ky ((nang dai) or (xang dau)) hoi. hieu ve cam ((luc van) OR (luu van)) hang hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((nang dai) OR (xang dau)) hoi. hieu ve cam ((luc van) OR (luu van)) hang hai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((nang dai) or (xang dau)) hoi. hieu ve cam ((luc van) OR (luu van)) hang hai cua te*".