Perhaps you should try some spelling variations:
sach tham » sach nha
phap thuc » phap thu, phap hoc, phap tu
nang ma » tang ma, sang ma, nang cao
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu
hieu v » hieu ve, hieu 2, hieu _
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sach thieu) or (sach tham)) nang ma hoi. ((hieu v) or (hieu va)) phap thuc va hanh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach thieu) OR (sach tham)) nang ma hoi. ((hieu v) OR (hieu va)) phap thuc va hanh vi cua tu.
• Adding a wildcard symbol may retrieve word variants: so ((sach thieu) or (sach tham)) nang ma hoi. ((hieu v) or (hieu va)) phap thuc va hanh vi cua tu*.