Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
la thay » bac thay
va thay » va tham, va hay, da thay
cao hoi » cau hoi, co hoi, cao hoc
ty nang » ky nang, ty xang, ty hang
cuu tre » cau tren, cau treo

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

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