Perhaps you should try some spelling variations:
thien van » thi van
van chat » cao chat
chat duc » chat xuc, chat doc, chet duoc
hanh tai » thanh tai, hang tai, han tai
so triet » su triet, bo triet, mao triet
so thiet » soc thiet, hoc thiet, hoa thiet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
va hanh » van hanh, va thanh, va danh

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 nang cao hoi. thien van chat duc va hanh tai ((so triet) or (so thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cao hoi. thien van chat duc va hanh tai ((so triet) OR (so thiet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang cao hoi. thien van chat duc va hanh tai ((so triet) or (so thiet))*.