Perhaps you should try some spelling variations:
sach nuoc » sach duoc, cac nuoc, bach tuoc
hanh lam » thanh lap, hanh kem, hanh va
hanh lai » hanh tai, thanh lap, thanh loi
sach ky » sac ky, sach ty, sach kem
va sach » van sach, va cach, a sach
hieu va » lieu va, hieu qua
nang ro » nang co, nang ho, nang ra
cua tre » cua te, cuu tre, cua triet
ro hoi » co hoi, o hoi, mo hoi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ky) or (sach y)) nang ro hoi. hieu va sach nuoc va ((hanh lai) OR (hanh lam)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) nang ro hoi. hieu va sach nuoc va ((hanh lai) OR (hanh lam)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) or (sach y)) nang ro hoi. hieu va sach nuoc va ((hanh lai) OR (hanh lam)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sach y)) nang ro hoi. hieu va sach nuoc va ((hanh lai) OR (hanh lam)) cua tre*.