Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
pham duy » pham duc
van hanh » van thanh, ban hanh, van anh
cua viet » ca viet, cua vat, cua dieu
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
x hoi » xa hoi, o hoi, x ho

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