Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
sach ty » sach y, sach tu, sach thu
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang ma hoi. hieu va cac ((xuc va) or (tuc va)) thanh san ((cua triet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ma hoi. hieu va cac ((xuc va) OR (tuc va)) thanh san ((cua triet) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ma hoi. hieu va cac ((xuc va) or (tuc va)) thanh san ((cua triet) or (va triet))*.