Seven common errors in finding exact solutions of nonlinear differential equations
It is seen, that the last expression is better for understanding, then the solution by Öziş and Aslan.
Example 5c. Solution of the modified Benjamin - Bona - Mahony equation by Yusufoǧlu 
Using the travelling wave the author  obtained the equation
Solution (6.5) has three arbitrary constants a0, b0 and b1, but in fact this solution can be simplified using the set of equalities
We can see, that solution (6.6) contains the only arbitrary constant .
Note that Eq.(6.3) can be easy transformed to the modified KdV equation and this equation is not the BBM equation.
Example 5d. Solutions of the fifth - order KdV equation by Chun 
The sixth solution by Chun (formula (30) ) can be simplified to the trivial solution as well
The thirteenth (as well as the fourteenth and the fifteenth) solution (formula (69) in paper ) is also constant as we can see from the equality
We recognized, that among seventeen solutions presented by Chun in his paper twelve solutions (25), (27), (28) (30), (49), (51) (53), (55), (57), (69), (70) and (71) satisfy the fifth-order KdV equation, but solutions (25), (30), (69), (70) and (71) are trivial ones (constants) and (51) is not the solitary wave solution. Six solutions (25), (27), (49), (53), (55) and (57) are solitary wave solutions, but these ones are known and can be found by means of other methods.
Example 5e. Solutions of the improved Boussinesq equation by Abdou and co -authors .
Using the Exp - function method Abdou and his co - authors looked for the solitary wave solutions of the improved Bouusinesq equation
In the travelling wave Eq.(6.13) takes the form
The authors found several solutions of Eq.(6.12). One of them takes the form
However this solution can be presented as
Solution (6.14) can be obtained by many methods.
We have often observed the fifth error studying the application of the Exp - function method.
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