Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thanh lai » thanh hai, thanh lap, thanh loi
cua viet » ca viet, hoa viet, cua vat
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
lai cua » dai cua, hai cua, lai chau
cau duc » cao duc, cau luc, chu duc
van cau » van dau, van hau, van chat
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai

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))) or (thuat sach)) ky nang o hai. hieu van cau duc va thanh lai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (su sach))) OR (thuat sach)) ky nang o hai. hieu van cau duc va thanh lai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((tu sach) OR (su sach))) or (thuat sach)) ky nang o hai. hieu van cau duc va thanh lai cua viet".
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) OR (su sach))) or (thuat sach)) ky nang o hai. hieu van cau duc va thanh lai cua viet*.