Perhaps you should try some spelling variations:
cac thoi » cac hop, cac tro, cac thu
vu sach » vu bach, su sach, vu khach
sach ly » sach y, sach lo, sach ty
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
cuu tre » cau tren, cau treo
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
ly nang » ky nang, ly hang, ly vang

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