Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
cau tren » cu tren, dau tren, ca tren
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((nang xa) or (nang ma)) hoi. hieu ve cam duc va hanh vi ((cau tren) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (nang ma)) hoi. hieu ve cam duc va hanh vi ((cau tren) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (nang ma)) hoi. hieu ve cam duc va hanh vi ((cau tren) or (cua viet))*.