Perhaps you should try some spelling variations:
tham nuoc » thay nuoc, thoat nuoc, nha nuoc
thai son » thai den, thai do, thai hoc
hieu van » hieu va, thien van, lieu va
te sach » toc sach
cuu tre » cau tren, cau treo
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cua triet, dua tren
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang

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