Perhaps you should try some spelling variations:
thien danh » thien dang, thien thanh, thien chanh
thien anh » tien anh, thien thanh, thien chanh
trinh dan » trinh han, trinh san, trinh dao
dung cong » dung trong
trinh da » trinh dao, trinh do, trinh va
tuc dung » thuc dung, tac dung, duc dung
cong hoa » dong hoa, dong hoc, hang hoa
hoa phan » hoa dan, co phan
phan lap » phan dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thien danh) or (thien anh)) - ((trinh dan) or (trinh da)) tuc dung cong hoa phan lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thien danh) OR (thien anh)) - ((trinh dan) OR (trinh da)) tuc dung cong hoa phan lap*.