Perhaps you should try some spelling variations:
lang hai » lang chai, lang thai, lang ha
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
su sach » so sach, vu sach
buu tre » cuu tre
sach ky » sac ky, sach y, sach ty
hai hoi » dai hoi, hai moi, hai hai
ky lang » ky nang, ky dang, ky tang
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: su sach ky lang hai hoi. hieu ((ve cam) or (va cam)) luc ((van hanh) OR (ban hanh)) tai buu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang hai hoi. hieu ((ve cam) OR (va cam)) luc ((van hanh) OR (ban hanh)) tai buu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky lang hai hoi. hieu ((ve cam) or (va cam)) luc ((van hanh) OR (ban hanh)) tai buu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky lang hai hoi. hieu ((ve cam) or (va cam)) luc ((van hanh) OR (ban hanh)) tai buu tre*.