Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
hau tren » cau tren, thai tren, chay tren
hieu van » hieu va, thien van, lieu va
dan hai » doan hai, dang hai, dan khai
cau tuc » cau truc, cau tu, cau luc
su sach » vu sach
so sach » so sanh, bo sach, co sach
sang ma » tang ma, nang ma, sang tao
van cau » van dau, van hau, van chat
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau
y sang » _ sang, duy sang

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) or (so sach)) y sang ma hoi. hieu van cau tuc va dan hai ((hau tren) OR (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) y sang ma hoi. hieu van cau tuc va dan hai ((hau tren) OR (dau tren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) y sang ma hoi. hieu van cau tuc va dan hai ((hau tren) OR (dau tren))*".