Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thi hang » thi hanh, thi nang, thi hong
hang cau » hang dau, hang ca, nhung cau
hieu cac » hieu luc, hieu va, hieu van
cac chat » cao chat, cac thuat, cac nha
vanh dan » canh dan, sanh dan, vanh dai
tu sach » thu sach, su sach, te sach
thai va » thai van
van dan » van ban, ban dan, van dao
su viet » so viet

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 cau hoi. hieu cac chat thai va ((vanh dan) OR (van dan)) su viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thi hang cau hoi. hieu cac chat thai va ((vanh dan) OR (van dan)) su viet".
• Adding a wildcard symbol may retrieve word variants: tu sach thi hang cau hoi. hieu cac chat thai va ((vanh dan) OR (van dan)) su viet*.