Perhaps you should try some spelling variations:
cac truc » cau truc, cac tru, cac trung
toc sach » hoc sach, doc sach, thuoc sach
ve triet » va trien, su triet
dinh sai » dinh tai, danh sai, dinh hai
dang xay » dang van, van xay
va dinh » van dinh, va kinh, va tinh
truc va » thuc va, thuc vat, trung va
hieu va » lieu va, hieu qua
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
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: ((te sach) OR (toc sach)) ky dang xay hoi. hieu va cac truc va dinh sai ((ve triet) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky dang xay hoi. hieu va cac truc va dinh sai ((ve triet) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky dang xay hoi. hieu va cac truc va dinh sai ((ve triet) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky dang xay hoi. hieu va cac truc va dinh sai ((ve triet) or (cua te))*.