Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach
thuat tach » thuat sach, thuat mach, thuat tac
hanh trinh » canh tranh, hanh chinh
nhung dung » phuong dung, ung dung, thong dung
trinh va » trinh van, trinh vat, trinh ve
van toan » van tan, van thanh, manh toan
van tuan » van quan, van ban, anh tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thiet tach) or (thuat tach)) - hanh trinh va nhung dung ((van toan) or (van tuan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet tach) OR (thuat tach)) - hanh trinh va nhung dung ((van toan) OR (van tuan)) ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet tach) or (thuat tach)) - hanh trinh va nhung dung ((van toan) or (van tuan)) ban*.