Perhaps you should try some spelling variations:
nang doc » nang luc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ra » nang ma, lang ra, nang ro
thuc xa » thuc xay, tuc xa, thuc va
xa hanh » xa thanh, xa khanh, va hanh
qua am » quan am, qua ap, cua am
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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 ky ((((nang noi) or (nang doc))) or (nang ra)) hoi. hieu qua am thuc xa hanh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((((nang noi) OR (nang doc))) OR (nang ra)) hoi. hieu qua am thuc xa hanh vi cua tu.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((((nang noi) or (nang doc))) or (nang ra)) hoi. hieu qua am thuc xa hanh vi cua tu*.