Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
cac hoc » cach hoc, cac hop, bac hoc
cuu tre » cau tren, cau treo
cac loc » cac lop, cac toc, cac nuoc
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang

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 ve ((cac loc) or (cac hoc)) va hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. hieu ve ((cac loc) OR (cac hoc)) va hanh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu ve ((cac loc) or (cac hoc)) va hanh vi ((cua tre) or (cuu tre))*.