Perhaps you should try some spelling variations:
thay nuoc » tham nuoc, tray nuoc, thoat nuoc
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
hanh tai » thanh tai, hang tai, han tai
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
va thay » va tham, la thay, va hay
hieu va » lieu va, hieu qua
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) OR (hoc sach)) ty nang cao hoi. hieu va 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) OR (hoc sach)) ty nang cao hoi. hieu va 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) OR (hoc sach)) ty nang cao hoi. hieu va thay nuoc va hanh tai ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (hoc sach)) ty nang cao hoi. hieu va thay nuoc va hanh tai ((cua tre) or (cuu tre))*.