Perhaps you should try some spelling variations:
thanh dat » thanh san, thanh hai, thanh van
thi hang » thi hanh, thi nang, thi hong
hanh dao » lanh dao, thanh dam, doanh dao
cam thuc » nam thuc, cam thu, can thuc
sach thi » sach thu, sach tai, sach thieu
tu sach » thu sach, su sach, te sach
su viet » so viet
hieu ve » hieu va, hieu van
hang xa » hoang xa, hang va, hang ca

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 thi hang xa hoi. hieu ve ((cam thuc) or (am thuc)) va ((hanh dao) OR (thanh dat)) su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thi hang xa hoi. hieu ve ((cam thuc) OR (am thuc)) va ((hanh dao) OR (thanh dat)) su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thi hang xa hoi. hieu ve ((cam thuc) or (am thuc)) va ((hanh dao) OR (thanh dat)) su viet".
• Adding a wildcard symbol may retrieve word variants: tu sach thi hang xa hoi. hieu ve ((cam thuc) or (am thuc)) va ((hanh dao) OR (thanh dat)) su viet*.