Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cua viet » hoa viet, cua vat, cua dieu
duy sang » duy van, duy can, duy anh
hanh vai » hanh vi, hanh va, hanh tai
cau tuc » cau truc, cau tu, cau luc
va hanh » van hanh, va thanh, va danh
ca viet » va viet, co viet, hoa viet
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
y sang » _ sang
tuc va » thuc va, truc va, tuc xa
ve cau » ke cau, va cau, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ((y sang) or (duy sang)) mai hoi. hieu ve cau tuc va hanh vai ((cua viet) OR (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((y sang) OR (duy sang)) mai hoi. hieu ve cau tuc va hanh vai ((cua viet) OR (ca viet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ((y sang) or (duy sang)) mai hoi. hieu ve cau tuc va hanh vai ((cua viet) OR (ca viet))*".