Perhaps you should try some spelling variations:
kmay nang » ky nang, kha nang, may nong
may nang » may nong, ky nang, cam nang
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
dinh vu » dich vu, dinh ve, dinh cu
ve cam » ve cham, ve cac, va cam
x hoi » xa hoi, o hoi, x ho
vu va » vu van, tu va, su va

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 ((may nang) or (kmay nang)) x hoi. hieu ve cam ((xuc van) OR (duc van)) dinh vu va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((may nang) OR (kmay nang)) x hoi. hieu ve cam ((xuc van) OR (duc van)) dinh vu va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((may nang) or (kmay nang)) x hoi. hieu ve cam ((xuc van) OR (duc van)) dinh vu va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((may nang) or (kmay nang)) x hoi. hieu ve cam ((xuc van) OR (duc van)) dinh vu va triet*.