Perhaps you should try some spelling variations:
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
cao hoi » cau hoi, co hoi, cao hoc
hieu ly » hieu ky, lieu ly, dieu ly
va hanh » van hanh, va thanh, va danh
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren
ly dat » ly dai, ly dao, ly mat
nuoc » quoc, duoc, ngoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sach ty) OR (sach tu)) nang cao hoi. hieu ly dat nuoc va hanh vi ((cuu tre) OR (cua tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach ty) OR (sach tu)) nang cao hoi. hieu ly dat nuoc va hanh vi ((cuu tre) OR (cua tre))".
• Adding a wildcard symbol may retrieve word variants: so ((sach ty) OR (sach tu)) nang cao hoi. hieu ly dat nuoc va hanh vi ((cuu tre) OR (cua tre))*.