Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
van hanh » van thanh, ban hanh, van anh
cau tren » cu tren, dau tren, ca tren
nang co » nang cao, nang doc, nang noi
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
tuc van » thuc van, truc van, tuc va
co hoi » co hoc, co loi
vi cau » va cau, ve cau, di cau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu hoach) or (thuat sach)) ky nang co hoi. ((hieu ve) or (lieu va)) cac tuc van hanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu hoach) OR (thuat sach)) ky nang co hoi. ((hieu ve) OR (lieu va)) cac tuc van hanh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: ((thu hoach) or (thuat sach)) ky nang co hoi. ((hieu ve) or (lieu va)) cac tuc van hanh vi cau tren*.