Each of the references is to an element on the periodic table.
a little Swedish town + a little Swedish town + a little Swedish town + a little Swedish town - a female scientist - a female scientist
a little Swedish town: four elements are named after the village of Ytterby in Sweden, Erbium (68), Terbium (65), Ytterbium (70), and Yttrium (39).
a female scientist: two elements have been named after female scientists, Curium (96) after Marie Curie and Meitnerium (109) after Lise Meitner.
68 + 65 + 70 + 39 - 96 - 109 = 37
America + California + Berkeley - Europe - France - France - Paris + Pluto - Uranus + a big Danish city - a big Swedish city
America: Americium (95)
California: Californium (98)
Berkeley: Berkelium (97)
Europe: Europium (63)
France: Francium (87) and Gallium (31)
Paris: Lutetium (71)
Pluto: Plutonium (94)
Uranus: Uranium (92)
a big Danish city: Hafnium (72) is named after Copenhagen
a big Swedish city: Holmium (67) is named after Stockholm
95 + 98 + 97 - 63 - 87 - 31 - 71 + 94 - 92 + 72 - 67 = 45
37 is Rubidium and 45 is Rhodium — the answer is Ruby Rhod. (A piece of trivia: he was actually named after those elements!).
(A piece of Taft trivia: the aforementioned fact is what inspired Ian to write the entire game.)