Perhaps you should try some spelling variations:
dang xay » dang van, van xay
cua viet » ca viet, cua vat, cua dieu
hanh hai » thanh hai, nhanh hai, hang hai
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
duc van » duc va, duc tan, duc manh
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc

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