Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thu sach » tu sach, thuat sach, thuoc sach
thi nang » thi cong, ki nang, thi hanh
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
nang xa » nang x, lang xa, nang ma
vai cua » dai cua, hai cua, bai cua
lai cua » dai cua, hai cua, lai chau
tuc va » thuc va, truc va, duc va

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

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