Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thuat duc » thuat duoc, thuat doc, thuat thuc
ve thuat » va thuat, ky thuat, ki thuat
dien cua » dieu cua, dien cuc, dien cu
vien cua » viec cua, tien cua, bien cua
so sach » so sanh, co sach, hoc sach
duc van » duc va, duc tan, duc manh
hieu ve » hieu va, hieu van
dang ha » dong ha, dung ha, lang ha
ky dang » ky nang, ky danh
bo sach » co sach, hoc sach
ha hoi » hoa hoi, ha noi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((so sach) or (bo sach)) ky dang ha hoi. hieu ve thuat duc van thanh ((vien cua) OR (dien cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (bo sach)) ky dang ha hoi. hieu ve thuat duc van thanh ((vien cua) OR (dien cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (bo sach)) ky dang ha hoi. hieu ve thuat duc van thanh ((vien cua) OR (dien cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (bo sach)) ky dang ha hoi. hieu ve thuat duc van thanh ((vien cua) OR (dien cua)) tre*.