Our dermatologist recommended this book to us many years ago (the product is now 12 years old). There were no male grandbabies on my husband's side of the family, and we really wanted a son for our second child. These tips in this book were well explained and rationalized. It worked for us!
All I can say about this book is that we had our daughter first and then wanted to make sure we had a boy second, so we bought the book. Our son Conner was born on May 27,2005. Do I need to say anything more?