Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
thi hang » thi hanh, thi nang, thi hong
cam thuc » am thuc, nam thuc, cam thu
cau treo » cau theo, cau tren, cau triet
tu sach » thu sach, su sach, te sach
co sach » bo sach, cuon sach
hang xa » hoang xa, hang va, hang ca
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
ve cam » ve cham, ve cac, va cam
vi cau » va cau, ve cau, di cau

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) or (((hoc sach) or (co sach)))) thi hang xa hoi. hieu ve cam thuc va hanh vi cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (((hoc sach) OR (co sach)))) thi hang xa hoi. hieu ve cam thuc va hanh vi cau treo.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (((hoc sach) or (co sach)))) thi hang xa hoi. hieu ve cam thuc va hanh vi cau treo*.