Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hien cac » thien cac, vien cac, hieu cac
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty hang, ly nang
va tinh » may tinh
tinh ki » trinh ki, tinh vi, tinh kien
ki su » ky su

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 ((ty nang) or (ty xang)) x ho. hieu hien cac nuoc va tinh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty xang)) x ho. hieu hien cac nuoc va tinh ki su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty xang)) x ho. hieu hien cac nuoc va tinh ki su triet*.