If one of the intervening states was a superpower, a civil war is a further 72% longer; a conflict such as the Angolan Civil War, in which there is two-sided foreign intervention, including by a superpower (actually, two superpowers in the case of Angola), would be 538% longer on average than a civil war without any international intervention.
Shellac is a wood finishing product made by dissolving dried resin in denatured alcohol. Shellac was used heavily for finishing furniture during the 19th and early 20th centuries, and it is still available for use today. The product is popular due to its ease of application, low odor, and all-natural origin.
Gel manicure is a type of manicure that uses a coat of gel applied on the nails, with regular polish on top. The use of UV light to cure the gel allows the manicure to last longer. Shellac is a technology invented by Creative Nail Design (CND). It is similar to regular nail polish, but also uses UV light in between coats, which make it last as long as gel manicures.