Perhaps you should try some spelling variations:
sach tham » sach nha
cam thuc » nam thuc, cam thu, can thuc
hanh dao » lanh dao, thanh dat, thanh dam
hoang xa » hoang ha, hoang va, hoang xuan
sach tai » sach bai, sach dao, sach xa
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va, hieu van
su viet » so viet
dao su » dao suu, dan su, cao su

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