@book{50191,
	author = {Pieters, G. A.},
	title = {The growth of sun and shade leaves of Populus euramericana robusta in relation to age, light intensity and temperature},
	publisher = {Veenman & Zonen,},
	year = {1974},
	series = {Mededelingen Landbouwhogeschool},
	address = {Washington :}
}