Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
cam truc » cau truc, nam truc, lam truoc
va thanh » gia thanh, ban thanh, le thanh
nam thuc » nam thuoc, am thuc, nam thu
sach ky » sac ky, sach y, sach ty
va tinh » may tinh
tu sach » thu sach, su sach, te sach
nang o » nang co, nang ho, nang ro
hai va » hai van, thai va, hoi va
o lai » o lao

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 ky nang o lai. lieu va ((cam truc) or (nam thuc)) ((va thanh) OR (va tinh)) hai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang o lai. lieu va ((cam truc) OR (nam thuc)) ((va thanh) OR (va tinh)) hai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang o lai. lieu va ((cam truc) or (nam thuc)) ((va thanh) OR (va tinh)) hai va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o lai. lieu va ((cam truc) or (nam thuc)) ((va thanh) OR (va tinh)) hai va triet*.