Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
dang xay » dang van, van xay
su triet » su viet, su tien, ve triet
nang xa » nang x, lang xa, nang ma
sach ky » sac ky, sach y, sach ty
van hac » van hoc, van ha, van chat
van hai » van ha, van chat, van hanh
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
tuc va » thuc va, truc va, tuc xa

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 ky ((nang xa) or (dang xay)) hoi. hieu ((van hac) OR (van hai)) tuc va hanh va su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (dang xay)) hoi. hieu ((van hac) OR (van hai)) tuc va hanh va su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((nang xa) or (dang xay)) hoi. hieu ((van hac) OR (van hai)) tuc va hanh va su triet".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (dang xay)) hoi. hieu ((van hac) OR (van hai)) tuc va hanh va su triet*.