Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
sach thu » sach thue, sach tham, cach thuc
danh vai » danh sai, danh va, doanh van
nang mai » nang ma, nang tai, lang mai
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
co duc » co duoc, cao duc, ho duc
do duc » dao duc, do duy

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach thu) or (sach thieu)) nang mai hoi. hieu va ((co duc) OR (do duc)) va danh vai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach thu) OR (sach thieu)) nang mai hoi. hieu va ((co duc) OR (do duc)) va danh vai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach thu) or (sach thieu)) nang mai hoi. hieu va ((co duc) OR (do duc)) va danh vai cua triet".
• Adding a wildcard symbol may retrieve word variants: te ((sach thu) or (sach thieu)) nang mai hoi. hieu va ((co duc) OR (do duc)) va danh vai cua triet*.