Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
dau tren » dau tien, dat tren, dau tieng
duc manh » suc manh, duc anh, duc minh
duc danh » duc anh, duc hanh, duc dan
hai dau » han dau, hai dan, hai hau
tu sach » thu sach, su sach, tu cach
te sach » toc sach
hieu ve » hieu va, hieu van
nang o » nang co, nang ho, nang ro
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
o hoc » co hoc, mo hoc, so hoc

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) y nang o hoc. hieu ve cam ((duc danh) OR (duc manh)) thanh hai dau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) y nang o hoc. hieu ve cam ((duc danh) or (duc manh)) thanh hai dau tren~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) y nang o hoc. hieu ve cam ((duc danh) or (duc manh)) thanh hai dau tren*.