M. L. Buchman 
Night and Day [EPUB ebook] 

-a Night Stalkers CSAR romance story-
The most dangerous mission of all…CSAR. Combat Search and Rescue.
Lieutenant Nicolai Martin often embellishes his Russian roots to impress the ladies. It works great until he tries it on the real deal. Unfortunately, to meet her required getting shot first.
Medic Gerta Kozlov attacks life with a fierce determination. It got her out of Russian-controlled Ukraine and into the Night Stalkers. But what use is fierce determination next to a man who just makes her want to smile Night and Day.