Perhaps you should try some spelling variations:
hoc thieu » toc thieu, hoc hien
dung cong » dung trong
doc hieu » toc thieu, hoc hien
hang cua » mang cua, huong cua, thong cua
cong tac » cong ty
tac nhan » tao nhan, cac nhan, dac nhan
nhan tap » nhan tai, nhan tao, han tap
hang ca » hang va, nang cao, hang tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc hieu) or (hoc thieu)) manh - hanh ((hang cua) or (hang ca)) dung cong tac nhan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (hoc thieu)) manh - hanh ((hang cua) OR (hang ca)) dung cong tac nhan tap*.