Complex sentence: Two books in "The Knowledge" series are "Murderous Maths" and "More Murderous Maths" however Kjartan Poskitt incorporated these two books and many others into their own Murderous Maths series.
Split into simpler sentences: Two books in "The Knowledge" series are "Murderous Maths" and "More Murderous Maths". However, Kjartan Poskitt incorporated these two books and many others into their own Murderous Maths series.