Missing spaces (#4441)

free-programming-books.md

@@ -410,7 +410,7 @@
 * [Computer Vision](http://homepages.inf.ed.ac.uk/rbf/BOOKS/BANDB/bandb.htm) - Dana Ballard, Chris Brown
 * [Computer Vision: Algorithms and Applications](http://szeliski.org/Book/) - Richard Szeliski
 * [Computer Vision: Models, Learning, and Inference](http://www.computervisionmodels.com) - Simon J.D. Prince
-* [Mastering OpenCV 4,Third Edition](https://www.packtpub.com/free-ebooks/mastering-opencv-4-third-edition) - Roy Shilkrot, David Millán Escrivá (Packt account *required*)
+* [Mastering OpenCV 4, Third Edition](https://www.packtpub.com/free-ebooks/mastering-opencv-4-third-edition) - Roy Shilkrot, David Millán Escrivá (Packt account *required*)
 * [Programming Computer Vision with Python](http://programmingcomputervision.com) - Jan Erik Solem
 
 
@@ -1010,7 +1010,7 @@ Kerridge (PDF) (email address *requested*, not required)
 
 ### Basic
 
-* [10 PRINT CHR$(205.5+RND(1)); : GOTO 10](http://10print.org) - Nick Montfort, Patsy Baudoin, John Bell,Ian Bogost, Jeremy Douglass, Mark C. Marino, Michael Mateas, Casey Reas, Mark Sample, Noah Vawter
+* [10 PRINT CHR$(205.5+RND(1)); : GOTO 10](http://10print.org) - Nick Montfort, Patsy Baudoin, John Bell, Ian Bogost, Jeremy Douglass, Mark C. Marino, Michael Mateas, Casey Reas, Mark Sample, Noah Vawter
 * [A beginner's guide to Gambas](http://distro.ibiblio.org/vectorlinux/Uelsk8s/GAMBAS/gambas-beginner-guide.pdf) - John W. Rittinghouse (PDF)
 * [Pick/Basic: A Programmer's Guide](http://www.jes.com/pb/) - Jonathan E. Sisk
 * [Visual Basic Essentials](http://www.techotopia.com/index.php/Visual_Basic_Essentials)