Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
sach vuc » sach duoc, sach nuoc, sach truc
vuc nang » cuc nang, vu nang, chuc nang
van hanh » van thanh, ban hanh, van anh
tham xuc » tham nuoc, pham duc, cam xuc
tu sach » thu sach, su sach, te sach
hanh ki » hanh vi, hanh ky, hanh kien
hieu va » lieu va, hieu qua
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) OR (tham thuc)) 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) OR (tham thuc)) 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) OR (tham thuc)) van hanh ki su viet".
• Adding a wildcard symbol may retrieve word variants: tu sach vuc nang ((ma hoi) or (ma hoa)). hieu va ((tham xuc) OR (tham thuc)) van hanh ki su viet*.