Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
lam truc » lam truoc, nam truc, lam thuoc
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
van lam » van nam
ca viet » va viet, co viet, hoa viet
nang ma » tang ma, sang ma, nang cao
lang ha » long ha
lang xa » dang xay, lang van
vi ca » vit ca, li ca, va ca

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach y ((((lang xa) OR (lang ha))) or (nang ma)) hoi. hieu van lam truc van hanh vi ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y ((((lang xa) OR (lang ha))) OR (nang ma)) hoi. hieu van lam truc van hanh vi ca viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach y ((((lang xa) OR (lang ha))) or (nang ma)) hoi. hieu van lam truc van hanh vi ca viet*".