Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, nam thuc
sach ky » sac ky, sach y, sach kem
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
tuc va » thuc va, truc va, tuc xa
va cam » va cham, va cac, va cao
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: co ((sach ky) OR (sach ty)) nang x hoi. hieu va cam tuc va hanh vi ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co ((sach ky) OR (sach ty)) nang x hoi. hieu va cam tuc va hanh vi ((cua tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "co ((sach ky) OR (sach ty)) nang x hoi. hieu va cam tuc va hanh vi ((cua tre) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: co ((sach ky) OR (sach ty)) nang x hoi. hieu va cam tuc va hanh vi ((cua tre) or (cau tren))*.