Perhaps you should try some spelling variations:
sach hoa » sach ha, bach hoa, cach hoan
hanh hai » thanh hai, nhanh hai, hang hai
sach hoi » sach doi, sach moi, cach thoi
nhan luc » nang luc
cham luc » cham soc, cham cuu, chat lua
hai cua » thai cua, dai cua, hoi cua
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va, hieu van
xac hoi » xa hoi, cac thoi, cac khoi
dan xac » dan bac, dan cac, dan xa
cua tre » cua te, cuu tre, cua triet

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 hoa) or (sach hoi)) dan xac hoi. hieu ve ((cham luc) OR (nhan luc)) va hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach hoa) OR (sach hoi)) dan xac hoi. hieu ve ((cham luc) OR (nhan luc)) va hanh hai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach hoa) or (sach hoi)) dan xac hoi. hieu ve ((cham luc) OR (nhan luc)) va hanh hai cua tre*".