Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
chat xuc » chat huu, cam xuc, chao xu
hieu van » thien van, lieu va, hieu ve
tu tong » tu tuong, tu trong, tu dong
cho hoc » co hoc, khoa hoc
hieu va » lieu va, hieu qua
xuc van » duc van, luc van, vuc van
tu nong » tu dong, tu cong, tu tuong
cua cau » cua cac, cua chu, cua cay
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((tu nong) OR (tu tong)) cho hoc. ((hieu van) or (hieu va)) chat xuc van hanh vi cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((tu nong) OR (tu tong)) cho hoc. ((hieu van) OR (hieu va)) chat xuc van hanh vi cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((tu nong) OR (tu tong)) cho hoc. ((hieu van) or (hieu va)) chat xuc van hanh vi cua cau*".