Perhaps you should try some spelling variations:
ncanh tinh » nhanh tinh, thanh tinh, hanh tinh
dang trong » dung trong, lang trong, dang trung
dong trong » duong trong, dung trong, cong trong
hien xanh » hien hanh, hien nhanh, chieu xanh
canh tinh » hanh tinh, manh tinh, canh tranh
san toan » van toan, dan toan, manh toan
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien xanh - ((canh tinh) or (ncanh tinh)) quang ((dang trong) OR (dong trong)) san toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - ((canh tinh) OR (ncanh tinh)) quang ((dang trong) OR (dong trong)) san toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien xanh - ((canh tinh) or (ncanh tinh)) quang ((dang trong) OR (dong trong)) san toan ban".
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - ((canh tinh) or (ncanh tinh)) quang ((dang trong) OR (dong trong)) san toan ban*.