Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
danh xay » dang xay, manh xay, anh xay
thuc van » thuc vat, thuc dan, thuc va
duc van » duc va, duc tan, duc manh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
xay hoi » xa hoi, tay hoi, cay phoi
ky danh » ky anh, ky dang
va cao » va cac, va co, va dao
va cam » va cham, va cac, va cai
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 ky danh xay hoi. hieu ((va cam) or (va cao)) ((thuc van) or (duc van)) hanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky danh xay hoi. hieu ((va cam) OR (va cao)) ((thuc van) OR (duc van)) hanh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ky danh xay hoi. hieu ((va cam) or (va cao)) ((thuc van) or (duc van)) hanh vi cau tren*.