Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
thu sach » thuat sach, thuoc sach, thu hoach
nang hoa » nang hoat, hang hoa, nang hoc
tinh ve » trinh ve, tinh ven, dinh ve
va tinh » may tinh
cac xuc » cam xuc, cac nuoc, chat xuc
tu sach » su sach, te sach, tu cach
hoa hoi » khoa hoi, hoa hoc, hoa doi
hieu va » hieu qua
xuc va » duc va, tuc va, luc va
ve va » ve van, te va, ke 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) or (thu sach)) ky nang hoa hoi. ((hieu va) OR (lieu va)) cac xuc va tinh ve va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang hoa hoi. ((hieu va) OR (lieu va)) cac xuc va tinh ve va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang hoa hoi. ((hieu va) OR (lieu va)) cac xuc va tinh ve va triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang hoa hoi. ((hieu va) OR (lieu va)) cac xuc va tinh ve va triet*.