Perhaps you should try some spelling variations:
hanh doi » thanh doi, hanh noi, hang doi
pham duy » pham duc
vu sach » vu bach, su sach, vu khach
cua tre » cuu tre, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
hieu vi » hieu voi, hieu va, hieu ve
sach ly » sach y, sach lo, sach ty
tang ma » mang may, tang van
duy va » duy vat, duy van, day va
cua te » cua tu

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 ly ((nang x) or (tang ma)) hoi. hieu vi pham duy va hanh doi ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ly ((nang x) OR (tang ma)) hoi. hieu vi pham duy va hanh doi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ly ((nang x) or (tang ma)) hoi. hieu vi pham duy va hanh doi ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: vu sach ly ((nang x) or (tang ma)) hoi. hieu vi pham duy va hanh doi ((cua tre) OR (cua te))*.