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