1. Ada, L.: adafruit/DHT-sensor-library (2017).
https://github.com/adafruit/DHT-sensor-library
2. Arduino.cc: (2015).
https://www.arduino.cc
3. Arduino.cc: Arduino LiquidCrystal Library (2015).
https://www.arduino.cc/en/Reference/LiquidCrystal
4. Arduino.cc: Arduino NewPing Library (2015).
http://playground.arduino.cc/Code/NewPing
5. Arduino.cc: Arduino Servo Library (2015).
https://www.arduino.cc/en/Reference/Servo