Perhaps you should try some spelling variations:
vuc nang » cuc nang, vu nang, chuc nang
sach vuc » sach duoc, sach nuoc, sach truc
tu sach » thu sach, su sach, te sach
hanh ki » hanh vi, hanh ky, hanh kien
duc van » duc va, duc tan, duc manh
xuc van » luc van, vuc van, xuc ban
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
su viet » so viet
ma hoi » mai hoi, xa hoi, me hoi
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 ((ma hoi) or (ma hoa)). hieu va tham ((xuc van) OR (duc van)) hanh ki su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vuc nang ((ma hoi) OR (ma hoa)). hieu va tham ((xuc van) OR (duc van)) hanh ki su viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach vuc nang ((ma hoi) or (ma hoa)). hieu va tham ((xuc van) OR (duc van)) hanh ki su viet*".