Perhaps you should try some spelling variations:
phap thuc » phap thu, phap hoc, phap tu
pham thuc » pham chuc, nham thuc, pham thu
sach thi » sach thu, sach tai, sach thieu
thi nang » thi cong, ki nang, thi hanh
hanh hai » thanh hai, nhanh hai, hang hai
so sach » so sanh, bo sach, co sach
nang ma » tang ma, sang ma, nang cao
va hanh » van hanh, va thanh, va danh
hai cua » thai cua, dai cua, hoi cua
ma hoi » mai hoi, xa hoi, ma hoa
hieu v » hieu va, hieu ve, hieu 2
cua te » cua tu

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 thi nang ma hoi. hieu v ((pham thuc) or (phap thuc)) va hanh hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thi nang ma hoi. hieu v ((pham thuc) OR (phap thuc)) va hanh hai cua te.
• Adding a wildcard symbol may retrieve word variants: so sach thi nang ma hoi. hieu v ((pham thuc) or (phap thuc)) va hanh hai cua te*.