@book{52,
	author = {Kotler, Philip and Armstrong, Gary},
	title = {Principles of marketing},
	publisher = {Pearson ,},
	year = {c2018},
	address = {Harlow, England :},
	edition = {17th ed.},
	note = {Includes index},
	url = {https://external.dandelon.com/download/attachments/dandelon/ids/AT002E260D0E874899D6FC125823C00392480.pdf}
}