I’m old fashioned, I like actual books. But I can give you some references and citations (if you know how to use Library Genesis or equivalent, you’ll download easily, although illegally, those books).

Although it was possible to justify the use of force in Christianization, we must distinguish between the use of violence in the consolidation of power and its employment against the population at large in order to make them convert. The first, war against rivals, some of whom were pagan, in order to establish or strengthen a ruler’s power, was prevalent. The latter did not often occur in these areas.

Nora Berend, Christianization and the rise of Christian monarchy: Scandinavia, Central Europe and Rus’ c. 900-1200, Cambridge University Press, 2007, p. 20-21.

Scholars have argued that if there had been serious, and violent, religious conflicts between non-Christians and Christians, this would have left traces in the rune stone material. They have, however, not found any such signs.

Alexandra Sanmark, Power and conversion: a comparative study of Christianization in Scandinavia; Uppsala: Department of Archaeology and Ancient History, 2002, p. 113-114.

Because – it must be strongly emphasized again – the conversion of Scandinavia will have taken place without drawing the sword, without religious wars, without bloodshed, without martyrdom. When chroniclers depict it to us, much later, under a tragic and violent exterior, they will only do so by imitation of the lives of saints which were de rigeur in the West at the time.

Régis Boyer, Les Vikings, Perrin, 2015, p. 402 (I translated).

Edit: But if you want something online to read, I believe that this page is quite accurate.