Perhaps you should try some spelling variations:
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
tu sach » thu sach, su sach, te sach
cac toc » cac toi, cac thoi
vat cua » mat cua, bat cua, dat cua
van vat » van chat, nhan vat
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
cac tac » cac bac, cac dac, cac tai
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
da van » dao van, dam van, va van

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky lang xa hoi. hieu va ((cac tac) or (((cac toc) OR (cac nuoc)))) da van vat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. hieu va ((cac tac) OR (((cac toc) OR (cac nuoc)))) da van vat cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. hieu va ((cac tac) or (((cac toc) OR (cac nuoc)))) da van vat cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu va ((cac tac) or (((cac toc) OR (cac nuoc)))) da van vat cua tre*.