Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
su triet » su viet, su tien, ve triet
dau sai » dau hai, dau tai, danh sai
cam duc » cam xuc, cao duc, pham duc
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cua tuc » cua duc, cua tu, cua thuoc
va cam » va cham, va cac, va cao
va dau » va dao

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 va cam duc va dau sai ((su triet) or (cua tuc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky lang xa hoi. hieu va cam duc va dau sai ((su triet) OR (cua tuc)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky lang xa hoi. hieu va cam duc va dau sai ((su triet) or (cua tuc))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky lang xa hoi. hieu va cam duc va dau sai ((su triet) or (cua tuc))*.