Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
hieu van » thien van, lieu va, hieu ve
chat duc » chat xuc, chat doc, chet duoc
va thanh » gia thanh, ban thanh, va tinh
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nang o » nang co, nang ho, nang ro
dai su » dai sua, dai so, dan su
o hai » co hai, so hai, o lai

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 ky nang o hai. ((hieu van) or (hieu va)) chat duc va thanh dai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang o hai. ((hieu van) OR (hieu va)) chat duc va thanh dai su triet.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang o hai. ((hieu van) or (hieu va)) chat duc va thanh dai su triet*.