Perhaps you should try some spelling variations:
thiet danh » thien danh, thien anh, thien dang
hanh trinh » canh tranh, hanh chinh
hoc thiet » hoc thieu, hoc thuyet, hoc hien
lang cong » dang cong, bang cong, hang cong
manh toan » thanh toan, anh tuan, tinh toan
trinh va » trinh van, trinh vat, trinh ve
dan toan » van toan, dan than, xuan toan
va lang » va nang, hoa lang

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 danh - hanh trinh va lang cong ((dan toan) or (manh toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet danh - hanh trinh va lang cong ((dan toan) OR (manh toan)) cau.
• Adding a wildcard symbol may retrieve word variants: hoc thiet danh - hanh trinh va lang cong ((dan toan) or (manh toan)) cau*.