Perhaps you should try some spelling variations:
thien van » thi van
thu sach » tu sach, thuat sach, thuoc sach
cau tren » cu tren, dau tren, ca tren
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
sach ky » sac ky, sach y, sach ty
cau tuc » cau truc, cau tu, cau luc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
van cau » van dau, van hau, van chat
tuc va » thuc va, truc va, tuc xa

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((nang xa) or (lang xa)) hoi. thien van cau tuc va hanh vi ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (lang xa)) hoi. thien van cau tuc va hanh vi ((cua tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (lang xa)) hoi. thien van cau tuc va hanh vi ((cua tre) or (cau tren))*.