BERLIN, Germany - Ferrari has indirectly criticised rival Formula 1 team Red Bull in a column on its website about the lingering tyre degradation issue.Without naming World champion Red Bull or its driver Sebastian Vettel, Ferrari's "horse whisperer" said that some may have forgotten that past races have also been won with a lot of pit stops.Vettel and his team, as well as Mercedes and a few others, have not been happy with the 2013 rubber provided by Pirelli, which has promised modifications after the upcoming Monaco GP.'DIFFICULT TIMES, POOR MEMORIES'Vettel finished fourth at the 2013 Spanish GP on May 12 after four pit stops, the same number needed by Ferrari's Fernando Alonso and Felipe Massa to win the race and come third, respectively."These are difficult times for people with poor memories," the column said. "Maybe the brain cells that control memory only operate selectively, depending on the results achieved on track by their owners."Ferrari referred to the Spanish and Turkish races in 2011 when five of the six podium finishers also won with four stops. Both races were won by Vettel."It seems one must almost feel ashamed for choosing a strategy that, as always for that matter, is aimed at getting the most out of the package one has available," the Ferrari column said.Lotus has also spoken out about the tyre degradation issue; team principal Eric Boullier said during an interview published on his team's website that he was not happy with the upcoming modifications even though he acknowledged that Pirelli was in a difficult situation.'SOMEWHAT FRUSTRATING'"There aren't many sports where there are such fundamental changes to an essential ingredient part-way through a season," Boullier said. "Just imagine for a moment that, because a football team can't run as fast as its opponent, the dimensions of the pitch are changed at half time!"That there are changes to come can be seen as somewhat frustrating. I hope they are not too extreme."Two-times champion Vettel is leading the 2013 championship with 89 points from Lotus driver Kimi Raikkonen (85) and Alonso (72).