Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
vu sach » vu bach, su sach, vu khach
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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) OR (doc sach)))) ky nang x hoi. hieu ve pham thuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (((toc sach) OR (doc sach)))) ky nang x hoi. hieu ve pham thuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (((toc sach) OR (doc sach)))) ky nang x hoi. hieu ve pham thuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (((toc sach) OR (doc sach)))) ky nang x hoi. hieu ve pham thuc va hanh vi cua tre*.