Perhaps you should try some spelling variations:
phap thuc » phap hoc, phap tu
day thanh » dao thanh, dat thanh, da thanh
thu tang » thu trang, thu thang, thu hang
thanh ca » thanh cha, thanh cac, thanh ha
thi hang » thi hanh, thi nang, thi hong
phap thu » phap tu, phap che
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
ca cua » co cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((thu tang) or (thi hang)) ma hoa. hieu va ((phap thuc) OR (phap thu)) day thanh ca cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((thu tang) OR (thi hang)) ma hoa. hieu va ((phap thuc) OR (phap thu)) day thanh ca cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((thu tang) or (thi hang)) ma hoa. hieu va ((phap thuc) OR (phap thu)) day thanh ca cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((thu tang) or (thi hang)) ma hoa. hieu va ((phap thuc) OR (phap thu)) day thanh ca cua tre*.