Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh doi » thanh doi, hanh noi, hang doi
doi cua » dai cua, hoi cua, dong cua
va hanh » van hanh, va thanh, va danh
te sach » toc sach
cua tre » cua te, cuu tre, cua triet
ve cai » va cai, ve cac, ve tai
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (te sach)) ky nang o hai. hieu ((ve cai) or (va cac)) duc va hanh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (te sach)) ky nang o hai. hieu ((ve cai) OR (va cac)) duc va hanh doi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (te sach)) ky nang o hai. hieu ((ve cai) or (va cac)) duc va hanh doi cua tre*.