Perhaps you should try some spelling variations:
khao khanh » khac khanh, khao nhanh, kho khan
phong thai » phong thi, thong thai, phong tai
cao nganh » cac nganh, cau nganh, tao nganh
hong thai » cong thai, hong ha, hinh thai
su khao » so khao, su khac, qua khao
su cao » cu cao, vu cao, su co
y khi » ly khi, ky khi, my khi

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( su cao nganh y khi đong luc ) OR ( su khao khanh ((phong thai) OR (hong thai)) đong luc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( su cao nganh y khi đong luc ) or ( su khao khanh ((phong thai) OR (hong thai)) đong luc ))~".
• Adding a wildcard symbol may retrieve word variants: (( su cao nganh y khi đong luc ) or ( su khao khanh ((phong thai) OR (hong thai)) đong luc ))*.