Perhaps you should try some spelling variations:
lang thai » lang chai, dang thai, lang hai
nang thai » nang tai, dang thai, nang hai
su triet » su viet, su tien, ve triet
cam thu » nam thu, cac thu, ca thu
tu sach » thu sach, te sach, tu cach
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
su sach » so sach, vu sach
thu va » thuc va, thue va, tu va
va cam » va cham, va cac, va cao

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)) ty nang xa hoi. hieu va cam thu va ((nang thai) OR (lang thai)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ty nang xa hoi. hieu va cam thu va ((nang thai) OR (lang thai)) su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ty nang xa hoi. hieu va cam thu va ((nang thai) OR (lang thai)) su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ty nang xa hoi. hieu va cam thu va ((nang thai) OR (lang thai)) su triet*.