Perhaps you should try some spelling variations:
phap thuc » phap thu, phap hoc, phap tu
pham thuc » pham chuc, nham thuc, pham thu
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
vu sach » vu bach, su sach, vu khach
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va, hieu van
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
cua tre » cua te, cuu tre, cua triet
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: ((vu sach) or (toc sach)) ky dang xay hoi. hieu ve ((pham thuc) OR (phap thuc)) va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (toc sach)) ky dang xay hoi. hieu ve ((pham thuc) OR (phap thuc)) va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (toc sach)) ky dang xay hoi. hieu ve ((pham thuc) OR (phap thuc)) va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (toc sach)) ky dang xay hoi. hieu ve ((pham thuc) OR (phap thuc)) va hanh vi cua tre*.