Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va triet » va thiet, va trien, ve triet
hanh sai » hanh san, hanh tai, danh sai
hieu van » hieu va, thien van, lieu va
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
van cam » van nam, van lam, van cau
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
tuc va » thuc va, truc va, tuc xa
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 lang xa hoi. hieu van cam tuc va hanh sai ((va triet) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky lang xa hoi. hieu van cam tuc va hanh sai ((va triet) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky lang xa hoi. hieu van cam tuc va hanh sai ((va triet) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky lang xa hoi. hieu van cam tuc va hanh sai ((va triet) or (cua te))*.