Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
va hanh » van hanh, va thanh, va danh
sach ky » sach y, sach ty, sach kem
nang ma » tang ma, sang ma, nang cao
hieu te » hieu ve, hien te, hieu he
ma hoi » mai hoi, xa hoi, ma hoa
sac ky » cac ky, sai ky
ban bo » ban do, ban co, ben bo
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: su ((sach ky) or (sac ky)) nang ma hoi. hieu te ((ban bo) OR (can bo)) va hanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang ma hoi. hieu te ((ban bo) OR (can bo)) va hanh vi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sac ky)) nang ma hoi. hieu te ((ban bo) OR (can bo)) va hanh vi cau tren".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sac ky)) nang ma hoi. hieu te ((ban bo) OR (can bo)) va hanh vi cau tren*.