Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh dao » lanh dao, thanh dat, thanh dam
trung va » truong va, trang va, trung ha
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
sach 2 » sach y
dao su » dao suu, dan su, cao su
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach 2 ((nang ma) OR (tang ma)) hoi. hieu ve cam ((trung va) or (thuc va)) hanh dao su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach 2 ((nang ma) OR (tang ma)) hoi. hieu ve cam ((trung va) OR (thuc va)) hanh dao su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach 2 ((nang ma) OR (tang ma)) hoi. hieu ve cam ((trung va) or (thuc va)) hanh dao su triet".
• Adding a wildcard symbol may retrieve word variants: su sach 2 ((nang ma) OR (tang ma)) hoi. hieu ve cam ((trung va) or (thuc va)) hanh dao su triet*.