Perhaps you should try some spelling variations:
sach thien » sach thieu, sach tien, cach thien
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
van cam » van nam, van lam, van cau
su sach » so sach, vu sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cuu tre » cau tren, cau treo
xuc va » duc va, tuc va, luc va

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