Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
cua tre » cua te, cua triet, dua tren
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cuu tre » cau tren, cau treo
nang xa » lang xa, nang ma, mang xa
ve cam » ve cham, ve cac, va cam
cam o » cham o, cam lo, ca o
o van » vo van, so van, do van

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 ky ((nang xa) or (nang x)) hoi. hieu ve cam o van hanh vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang xa) OR (nang x)) hoi. hieu ve cam o van hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang xa) or (nang x)) hoi. hieu ve cam o van hanh vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (nang x)) hoi. hieu ve cam o van hanh vi ((cua tre) OR (cuu tre))*.