diff --git a/README.md b/README.md
index cb2d08e90e3d62dab04d69dd73283c7c07e4efe8..647b2978fc5e378c35d25592e1dff305d25de0a1 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,7 @@
     - filter electrospinning
     - CPAP helmet
     - CPAP instrumented machine
+        - https://www.researchgate.net/profile/Suelia_Fleury_Rosa/publication/289860451_Control_system_for_continuous_positive_airway_pressure/links/5874e6b008ae6eb871c97cea/Control-system-for-continuous-positive-airway-pressure.pdf
 - DIY mask materials
     - https://smartairfilters.com/en/blog/best-materials-make-diy-face-mask-virus/
     - https://www.researchgate.net/publication/258525804_Testing_the_Efficacy_of_Homemade_Masks_Would_They_Protect_in_an_Influenza_Pandemic