Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
ban hanh » ban hang
sach ky » sac ky, sach y, sach ty
va danh » va dinh, va dan, va hanh
vu sach » vu bach, su sach, vu khach
nang ma » tang ma, sang ma, nang cao
va cam » va cham, va cac, va cao
ve cam » ve cham, ve cac, ve cai
ma hoi » mai hoi, xa hoi, ma hoa
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: vu sach ky nang ma hoi. hieu ((ve cam) OR (va cam)) xuc ((ban hanh) or (va danh)) vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang ma hoi. hieu ((ve cam) OR (va cam)) xuc ((ban hanh) OR (va danh)) vi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang ma hoi. hieu ((ve cam) OR (va cam)) xuc ((ban hanh) or (va danh)) vi cau tren".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang ma hoi. hieu ((ve cam) OR (va cam)) xuc ((ban hanh) or (va danh)) vi cau tren*.