Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
cua nuoc » cua quoc, cua nguoi, cua thuoc
hieu van » hieu va, thien van, lieu va
nam duoc » nam thuoc, da duoc, dat duoc
nang ho » nang hoc, nang co, tang ho
va danh » va dan, va hanh, dia danh
va dinh » van dinh, va kinh, va tinh
vai cua » dai cua, hai cua, lai cua
tu sach » thu sach, su sach, te sach
ho hoc » hoa hoc, cho hoc, hoi hoc

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 (thuat sach)) ky nang ho hoc. hieu van nam duoc ((va danh) OR (va dinh)) vai cua nuoc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuat sach)) ky nang ho hoc. hieu van nam duoc ((va danh) OR (va dinh)) vai cua nuoc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuat sach)) ky nang ho hoc. hieu van nam duoc ((va danh) OR (va dinh)) vai cua nuoc".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuat sach)) ky nang ho hoc. hieu van nam duoc ((va danh) OR (va dinh)) vai cua nuoc*.