Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
thu sach » thuat sach, thuoc sach, thu hoach
kham tuc » nham thuc, pham thuc, kham cuoc
va hanh » van hanh, va thanh, va danh
vu kham » vu khanh
hieu vu » hieu va, hieu ve, hieu su
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua

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) or (thu sach)) va ((nang xa) OR (nang ma)) hoi. hieu vu kham tuc va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) va ((nang xa) OR (nang ma)) hoi. hieu vu kham tuc va hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) va ((nang xa) OR (nang ma)) hoi. hieu vu kham tuc va hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) va ((nang xa) OR (nang ma)) hoi. hieu vu kham tuc va hanh vi cua viet*.