Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hanh lai » hanh lam, hanh tai, thanh lap
su triet » su tien, ve triet
co sach » bo sach, cuon sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
su viet » so viet
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
cam tu » cam thu, nam tu, dam tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((co sach) OR (hoc sach)) y nang xa hoi. hieu ve cam tu va hanh lai ((su triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((co sach) OR (hoc sach)) y nang xa hoi. hieu ve cam tu va hanh lai ((su triet) OR (su viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((co sach) OR (hoc sach)) y nang xa hoi. hieu ve cam tu va hanh lai ((su triet) or (su viet))".
• Adding a wildcard symbol may retrieve word variants: ((co sach) OR (hoc sach)) y nang xa hoi. hieu ve cam tu va hanh lai ((su triet) or (su viet))*.