Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
doanh khoa » toan khoa
hoc doanh » hoa doanh, hoc danh, hoc dan
khoa hoc » hoa hoc
van toan » van tuan, van tan, van thanh
toan tai » toan tap, doanh tai, toan ban
hoi tap » hoc tap, hoi tai, hai tap
cuu mon » cuu mo, cuu mot, cuu cong
mon hoc » toan hoc, dong hoc
hai van » thai van, ha van, hai tan
ma hai » ta hai, va hai, xa hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ((hoi tap) or (hoi dap)), nghien cuu mon hoc doanh khoa hoc ma hai van toan tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ((hoi tap) OR (hoi dap)), nghien cuu mon hoc doanh khoa hoc ma hai van toan tai.
• Adding a wildcard symbol may retrieve word variants: thuat sach ((hoi tap) or (hoi dap)), nghien cuu mon hoc doanh khoa hoc ma hai van toan tai*.