Perhaps you should try some spelling variations:
vien cac » vien bach, vien da, gian cac
vien dai » hien dai
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
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 dai)) nuoc va tinh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x ho. hieu ((vien cac) OR (vien dai)) 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 dai)) nuoc va tinh ki su triet*.