A bibliography is an alphabetical list of all the works you have cited to get information about your topic. It can be a magazine, book, encyclopedia etc.
The strength increases as the copper content of the gutters increases. Copper rain gutters and roofing material in general are easy to install compared to traditional materials like slates, tiles, and cedar. A copper gutter adds great value to the aesthetic looks of a house.
If the roofing is of copper then copper rain gutters are strongly recommended to avoid compatibility issues and corrosion due to electrolysis. Aluminium gutters can be damaged and shredded during cleaning. This enables copper sheets to be moulded into the desired shapes to form accessories for rain gutters.