Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
sach ky » sac ky, sach y, sach ty
dan vai » dan va, dan tai, dan vat
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
tuc va » thuc va, truc va, duc va

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 ((tuc va) or (tuc xa)) dan vai ((cua triet) OR (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. hieu va cac ((tuc va) OR (tuc xa)) dan vai ((cua triet) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. hieu va cac ((tuc va) or (tuc xa)) dan vai ((cua triet) OR (va triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu va cac ((tuc va) or (tuc xa)) dan vai ((cua triet) OR (va triet))*.