Perhaps you should try some spelling variations:
van nhanh » van thanh, van hanh, van khanh
nhanh hai » nhanh thai, thanh hai, nhanh ha
dau tren » dau tien, dat tren, dau tieng
tu sach » thu sach, su sach, te sach
duc van » duc va, duc tan, duc manh
hai dau » han dau, hai dan, hai hau
y nang » ky nang, ly nang, v nang
va cam » va cham, va cao, va cai
x hoi » xa hoi, o hoi, x ho

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 y nang x hoi. hieu ((va cam) or (va cac)) duc van nhanh hai dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu ((va cam) OR (va cac)) duc van nhanh hai dau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu ((va cam) or (va cac)) duc van nhanh hai dau tren*.