Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, gian cac
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
vien da » vien dai, hien dai
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 x ho. hieu ((vien cac) OR (vien da)) nuoc va tinh ki su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x ho. hieu ((vien cac) OR (vien da)) nuoc va tinh ki su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x ho. hieu ((vien cac) OR (vien da)) nuoc va tinh ki su triet*.