Mobile phone group Vodafone's first quarter revenue was better than expected, according to Citi, which keeps its "buy" recommendation on the stock.Turning to the markets Vodafone operates in, Citi notes that Spain deteriorated as expected and the UK slowed, but Greece improved off a low base and India, South Africa and Turkey saw strong growth. "Although Netherlands saw slowing text revenue growth, and Spain has yet to feel the full impact of its price cuts, some early evidence of commercial progress there and sequential improvements in Italy and Germany are positives in our view," the broker observes.Citi keeps its 195p target price on Vodafone.