Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
chua tre » chua tri, chua trieu, cho tre
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
cac tuc » cac toc, cac tu, cac tac
hanh ca » hanh cac, hanh cat, hanh cua
tuc van » thuc van, truc van, tuc va
hieu ve » hieu va, hieu van
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (thuat sach)) ky sang ma hoi. hieu ve cac tuc van hanh ca ((chua tre) OR (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (thuat sach)) ky sang ma hoi. hieu ve cac tuc van hanh ca ((chua tre) OR (cua tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (thuat sach)) ky sang ma hoi. hieu ve cac tuc van hanh ca ((chua tre) OR (cua tre))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (thuat sach)) ky sang ma hoi. hieu ve cac tuc van hanh ca ((chua tre) OR (cua tre))*.