Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
thuc dan » thuc hanh, hoc dan, thuc vat
cua viet » ca viet, hoa viet, cua vat
sang ma » tang ma, sang tao, mang may
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc day
nang ma » tang ma, nang cao, mang may
va tham » van tham, va cham, va thanh
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: thu sach ky ((nang ma) OR (sang ma)) hoa. hieu va tham ((thuc va) or (thuc dan)) hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang ma) OR (sang ma)) hoa. hieu va tham ((thuc va) OR (thuc dan)) hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((nang ma) OR (sang ma)) hoa. hieu va tham ((thuc va) or (thuc dan)) hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang ma) OR (sang ma)) hoa. hieu va tham ((thuc va) or (thuc dan)) hanh vi cua viet*.