Perhaps you should try some spelling variations:
cham truc » cau truc, nham thuc, pham thuc
cua viet » ca viet, hoa viet, cua vat
dan dai » dat dai, can dai, dan dat
truc va » thuc va, thuc vat, trung va
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
tu sach » thu sach, te sach, tu cach
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
su sach » so sach, vu sach
va dan » ca dan, va dao, va dau

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) OR (su sach)) ((ky lang) or (ky dang)) xa hoi. hieu ve cham truc va dan dai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ((ky lang) OR (ky dang)) xa hoi. hieu ve cham truc va dan dai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ((ky lang) or (ky dang)) xa hoi. hieu ve cham truc va dan dai cua viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ((ky lang) or (ky dang)) xa hoi. hieu ve cham truc va dan dai cua viet*.