Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cham vuc » cham soc, pham duc, cham cuu
sach vuc » sach duoc, sach nuoc, sach truc
tu sach » thu sach, su sach, te sach
vuc van » duc van, luc van, thuc van
va cham » va chat, va tham
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
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: tu sach vuc ((nang xa) or (lang xa)) hoi. hieu va cham vuc van hanh ((vi su) or (ki su)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vuc ((nang xa) OR (lang xa)) hoi. hieu va cham vuc van hanh ((vi su) OR (ki su)) viet.
• Adding a wildcard symbol may retrieve word variants: tu sach vuc ((nang xa) or (lang xa)) hoi. hieu va cham vuc van hanh ((vi su) or (ki su)) viet*.