You Can Be Serious is Adrian Nicklin's book on sports psychology, primarily written for tennis players, but applicable to anyone who plays sports.
To quote from the preface:-
"You Can Be Serious is written for anybody and everybody that loves to play the game of tennis, with the core purpose of helping them become a better, happier and more fulfilled player with a cool, calm and composed manner on court.
As a result, this book is primarily for players, of any age. But it can double as a valuable resource for coaches and parents of junior players wishing to improve a young player under their tutelage and support.
Whether you are a social club player seeking to add a extra edge, or a performance player who wants to climb to the next level, I am confident you will find the contents of You Can Be Serious valuable. The methods and exercises I will explain have enabled me to help hundreds of players improve their game - and in many cases enjoy more satisfaction in their life in general."