Perhaps you should try some spelling variations:
chau triet » cau triet, cua triet, cau trieu
hanh tai » thanh tai, hang tai, han tai
hanh lai » hanh lam, thanh lap, thanh loi
hieu van » hieu va, thien van, lieu va
duc van » duc va, duc tan, duc manh
tu sach » thu sach, te sach, tu cach
van cau » van dau, van hau, van chat
cao hoi » cau hoi, co hoi, cao hoc
su sach » so sach, vu sach
cau duc » cao duc, cau luc, chu duc
y nang » ky nang, ly nang, v nang

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

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