Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
vien cac » vien bach, vien dai, vien da
duc van » duc va, duc tan, duc manh
nang ma » tang ma, sang ma, nang cao
hai hai » khai hai, dai hai, tai hai
ha chau » hat chau, a chau, lai chau
tu sach » thu sach, su sach, te sach
ve cam » ve cham, ve cac, va cam
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa

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 ma hoi. hieu ((ve cam) or (vien cac)) duc van hanh ((hai hai) or (ha chau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ma hoi. hieu ((ve cam) OR (vien cac)) duc van hanh ((hai hai) OR (ha chau)) treo.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ma hoi. hieu ((ve cam) or (vien cac)) duc van hanh ((hai hai) or (ha chau)) treo*.