Perhaps you should try some spelling variations:
vien cac » vien bach, vien da, gian cac
vien dai » hien dai
tu sach » thu sach, su sach, te sach
hang vi » hang va, hanh vi, hang di
va hang » van hang, va nang, va lang
cuu tre » cua tre, cau tren, cau treo
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, mang may
tuc va » thuc va, truc va, tuc xa
vi cuu » vi luu, vinh cuu

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 ky ((nang ma) or (nang cao)) hoa. hieu ((vien cac) OR (vien dai)) tuc va hang vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang ma) OR (nang cao)) hoa. hieu ((vien cac) OR (vien dai)) tuc va hang vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang ma) or (nang cao)) hoa. hieu ((vien cac) OR (vien dai)) tuc va hang vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) or (nang cao)) hoa. hieu ((vien cac) OR (vien dai)) tuc va hang vi cuu tre*.