Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
van chat » cao chat
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
chat xuc » chat huu, cam xuc, chao xu
sach ky » sac ky, sach y, sach kem
cao hoi » cau hoi, co hoi, cao hoc
sach ty » sach y, sach tu, sach thu
su viet » so viet
vi su » va su, ve su, ki su

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) OR (sach ty)) nang cao hoi. hieu van chat xuc ((van hanh) or (ban thanh)) vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang cao hoi. hieu van chat xuc ((van hanh) OR (ban thanh)) vi su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang cao hoi. hieu van chat xuc ((van hanh) or (ban thanh)) vi su viet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang cao hoi. hieu van chat xuc ((van hanh) or (ban thanh)) vi su viet*.