https://developer.paypal.com/docs/api/


https://developer.paypal.com/docs/


https://developer.paypal.com/docs/integration/mobile/mobile-sdk-overview/


https://developer.paypal.com/docs/integration/admin/manage-apps/


https://github.com/paypal/PayPal-Android-SDK#add-the-sdk-to-your-project


https://developer.paypal.com/webapps/developer/docs/classic/mobile/gs_MPL/




http://tutorials-android.blogspot.kr/2012/05/paypal-intigration-in-android.html  <<==good



http://www.slideshare.net/rschwentker/paypal-mobilepayments



http://stackoverflow.com/questions/18504286/paypal-integration-to-android-application



http://androidcodeexamples.blogspot.kr/2012/06/how-to-integrate-paypal-in-android.html



http://sunil-android.blogspot.kr/2013/10/paypal-android-sdk-with-multiple-in-app.html  <<==Great


https://devblog.paypal.com/working-with-the-new-android-sdk/   <<==Great


http://www.hasmukhbhadani.com/2012/05/paypal-integration-in-android.html


http://ask2mujahed.wordpress.com/2013/07/08/java-paypal-integration-tutorial-1/


http://kishor273.blogspot.kr/2011/07/paypal-integration-in-android.html


https://www.youtube.com/watch?v=NUXtFb1KwPQ


https://www.youtube.com/watch?v=QTO5a1IeBl8