Perhaps you should try some spelling variations:
thieu nien » thien nhien
cac nuoc » hoc nuoc, dat nuoc, cua nuoc
cap nuoc » dat nuoc
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
vi su » va su, ve su, ki 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. thieu nien ((cac nuoc) OR (cap nuoc)) ((va tinh) or (may tinh)) vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x ho. thieu nien ((cac nuoc) OR (cap nuoc)) ((va tinh) OR (may tinh)) vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x ho. thieu nien ((cac nuoc) OR (cap nuoc)) ((va tinh) or (may tinh)) vi su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x ho. thieu nien ((cac nuoc) OR (cap nuoc)) ((va tinh) or (may tinh)) vi su triet*.