Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
luc van » luoc van, luu van, duc van
cau luc » cau truc, cau phuc
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
ty tang » tay tang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, me hoi
ve cau » ke cau, va cau, ve cac
vi su » va su, ve su, oi su
ki su » ky su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty tang ((ma hoi) or (ma hoa)). hieu ve cau luc van hanh ((vi su) or (ki su)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty tang ((ma hoi) OR (ma hoa)). hieu ve cau luc van hanh ((vi su) OR (ki su)) viet.
• Adding a wildcard symbol may retrieve word variants: su sach ty tang ((ma hoi) or (ma hoa)). hieu ve cau luc van hanh ((vi su) or (ki su)) viet*.