Access to the public knowledge base is a key prerequisite for the good functioning of developed economies. Universities strive and are also requested to contribute to this goal at two levels: local and world-wide. Traditional studies on the geography of knowledge flows detect a localisation effect, but do not use the country as a unit of observation and hence do not explore national patterns in this localisation. In this paper, we hypothesise that the localisation of university knowledge flows is directly related to the country?s firms share in R&D expenditure. To test this hypothesis, we use university references from patent documents as indicators. We present a data set with about 20,000 university references for 37 countries in the period 1990-2007. We build indicators on the circulation of university knowledge flows inside and outside the applicant country and explain them as a function of some proxies for national scientific size and structure through econometric estimations. We draw conclusions on the importance of national business scientific strength to foster larger shares of domestic university knowledge flows.