Perhaps you should try some spelling variations:
dang khoa » dung khoa, hang khoa, dang khoi
hoc sach » hoc sinh, hoc cac, hoc anh
ban hanh » ban hang
cau tren » cu tren, dau tren, ca tren
khoa hoc » hoa hoc
qua cam » qua cham, qua cac, qua ca
tu dang » thu dang, tu dong, su dang
sach tu » sach thu, cach tu, sach ty
va danh » va dinh, va dan, va hanh
cuu tre » cua tre, cau treo

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 tu dang khoa hoc. hieu qua cam xuc ((ban hanh) or (va danh)) vi ((cuu tre) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach tu dang khoa hoc. hieu qua cam xuc ((ban hanh) OR (va danh)) vi ((cuu tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach tu dang khoa hoc. hieu qua cam xuc ((ban hanh) or (va danh)) vi ((cuu tre) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: hoc sach tu dang khoa hoc. hieu qua cam xuc ((ban hanh) or (va danh)) vi ((cuu tre) OR (cau tren))*.