สูตรชุดเดียว 3ตัวบน 16/05/62 (สูตรใหม่ เข้า4งวด)
The development of radar has been a tremendous boon to aviation since its first inception. Now we can fly to any destination, in all kinds of weather with complete confidence in our safety, all due in great part to avionics in general and radar in particular.
from: http://ezinearticles.com/?Radar---The-Early-Days-of-Development&id=193167
