Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thu sach » tu sach, thuat sach, thuoc sach
nang di » nang du, hang di, nang ji
thuc va » thuc vat, thuc dan, thuc day
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
ky lang » ky nang, ky dang, ky tang
ve cac » va cac, vien cac
tuc va » truc va, tuc xa, duc va
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cac) or (thu sach)) ky lang xa hoi. hieu ve cac ((tuc va) OR (thuc va)) nang di cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cac) OR (thu sach)) ky lang xa hoi. hieu ve cac ((tuc va) OR (thuc va)) nang di cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cac) or (thu sach)) ky lang xa hoi. hieu ve cac ((tuc va) OR (thuc va)) nang di cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu cac) or (thu sach)) ky lang xa hoi. hieu ve cac ((tuc va) OR (thuc va)) nang di cua triet*.