What kinds of numbers do students assign to literal symbols? Aspects of the transition from arithmetic to algebra KP Christou, S Vosniadou Mathematical Thinking and Learning 14 (1), 1-27, 2012 | 103 | 2012 |

What fills the gap between discrete and dense? Greek and Flemish students’ understanding of density X Vamvakoussi, KP Christou, L Mertens, W Van Dooren Learning and Instruction 21 (5), 676-685, 2011 | 83 | 2011 |

Students’ interpretations of literal symbols in algebra KP Christou, S Vosniadou, X Vamvakoussi Reframing the conceptual change approach in learning and instruction, 283-297, 2007 | 64 | 2007 |

Natural number bias in operations with missing numbers KP Christou ZDM 47, 747-758, 2015 | 47 | 2015 |

How students interpret literal symbols in algebra: A conceptual change approach KP Christou, S Vosniadou Proceedings of the Annual Meeting of the Cognitive Science Society 27 (27), 2005 | 32 | 2005 |

Bridging psychological and educational research on rational number knowledge X Vamvakoussi, KP Christou, S Vosniadou Journal of Numerical Cognition 4 (1), 84-106, 2018 | 29 | 2018 |

Difficulties in solving algebra story problems with secondary pupils K Christou PQDT-UK & Ireland, 2001 | 22 | 2001 |

Transitioning from arithmetic to algebra: Interpreting literal symbols as representing natural numbers KP Christou, S Vosniadou Mathematical Thinking and Learning 14, 1-27, 2012 | 14 | 2012 |

Greek and Flemish students’ interpretation of the literal symbols as variables W Van Dooren, KP Christou, X Vamvakoussi Mathematics in different settings–Proceedings of the 34th Conference of the …, 2010 | 12 | 2010 |

Misinterpreting the use of literal symbols in Algebra K Christou, S Vosniadou 33rd Conference of the International Group for the Psychology of Mathematics …, 2009 | 12 | 2009 |

Helping students remedy the phenomenal sign bias: The case of a refutational lecture KP Christou Proceedings of the 8th International Conference on Education, 643-648, 2012 | 10 | 2012 |

Prospective evAluatIon foR inhalation devices in Greek patients with COPD and asthma: the PAIR study T Karampitsakos, G Hillas, E Zervas, P Bakakos, G Stratakos, K Dimakou, ... Pulmonary Pharmacology & Therapeutics 60, 101882, 2020 | 9 | 2020 |

Natural number bias in arithmetic operations with missing numbers–a reaction time study KP Christou, C Pollack, J Van Hoof, W Van Dooren Journal of Numerical Cognition 6 (1), 22-49, 2020 | 6 | 2020 |

Natural number bias in operations with missing numbers. ZDM Mathematics Education, 47 (5), 747-758 KP Christou | 6 | 2015 |

Natural number bias on evaluations of the effect of multiplication and division: the role of the type of numbers KP Christou, X Vamvakoussi Mathematics Education Research Journal 35 (3), 427-443, 2023 | 5 | 2023 |

Greek and Flemish students’ understanding of the density of rational numbers: More similar, than different X Vamvakoussi, KP Christou, W Van Dooren Proceedings of PME 34 4, 249-256, 2010 | 5 | 2010 |

Interpreting literal symbols in algebra under the effects of the natural number bias KP Christou, DI Kyrvei, X Vamvakoussi Mathematical Thinking and Learning, 1-14, 2022 | 4 | 2022 |

Using refutational text to address the multiplication makes bigger misconception KP CHRISTOU, A PROKOPOU Educational Journal of the University of Patras UNESCO Chair 7 (1), 2020 | 4 | 2020 |

Tackling the natural number bias. A comparative textbook analysis W Van Dooren, K Christou, F Depaepe, M Inglis, S Määtä, J McMullen, ... 18th Biennial Conference of the European Association for Research on …, 2019 | 4 | 2019 |

The Dual Aspect of Natural Numbers Bias in Arithmetic Operations KP Christou Mediterranean Journal for Research in Mathematics Education, 107-121, 2017 | 4 | 2017 |