Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
luc van » luoc van, luu van, duc van
buu tre » cuu tre
hai hoi » dai hoi, hai moi, hai hai
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
va cam » va cham, va cac, va cao
ve cam » ve cham, ve cac, ve cai

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 lang) OR (ky tang)) hai hoi. hieu ((ve cam) or (va cam)) luc van hanh tai buu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky tang)) hai hoi. hieu ((ve cam) OR (va cam)) luc van hanh tai buu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky lang) OR (ky tang)) hai hoi. hieu ((ve cam) or (va cam)) luc van hanh tai buu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) OR (ky tang)) hai hoi. hieu ((ve cam) or (va cam)) luc van hanh tai buu tre*.