Perhaps you should try some spelling variations:
cham tuc » nham thuc, pham thuc, tham thuc
tu sach » thu sach, su sach, te sach
ca tren » cau tren, cu tren, co tren
sach ky » sac ky, sach y, sach ty
la tren » loai tren, dua tren, dat tren
va cham » va chat, va tham
hieu va » lieu va, hieu qua
cao hoi » cau hoi, co hoi, cao hoc
va dan » va dao, va dau, va dap
ca dan » cac dan, ca dao

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 ky nang cao hoi. hieu va cham tuc ((va dan) or (ca dan)) cua ((ca tren) OR (la tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cao hoi. hieu va cham tuc ((va dan) OR (ca dan)) cua ((ca tren) OR (la tren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang cao hoi. hieu va cham tuc ((va dan) or (ca dan)) cua ((ca tren) OR (la tren))*".