@article {43824,
	title = {Different classification systems in the Diptera},
	journal = {Annales Zoologici Fennici},
	volume = {19},
	year = {1985},
	pages = {209-219},
	abstract = {The ar ticle reviews and compares different systems in the primary classificati on of the order Diptera, including the traditional ones and those of recent catalogues, the cladistic works by Hennig, Griffiths and Steyskal, and Rohdendorf{\textquoteright}s evolutionary system as well as the ecological classification by Oldroyd. In addition, cytological evidence is considered. As a synthesis of these conflicting points of view a new higher classification of the Diptera is provisionally suggested.},
	url = {http://www.online-keys.net/sciaroidea/1981_90/Hackman\&Vaisanen_1982_ocr.pdf},
	author = {Hackman, Walter and V{\"a}is{\"a}nen, Rauno}
}
@article {22134,
	title = {Phronia matilei n. sp.,  a new fungus gnat from caves in Switzerland (Diptera: Mycetophilidae)},
	journal = {Notulae Entomologicae},
	volume = {52},
	year = {1972},
	pages = {39-40},
	url = {http://www.online-keys.net/sciaroidea/add01/Hackman_1972_Phronia_matilei_sp_n.pdf},
	author = {Hackman, Walter}
}
@article {22132,
	title = {New species of the genus Phronia Winnertz (Diptera, Mycetophilidae) from Eastern Fennoscandia and notes on the synonymies in this genus},
	journal = {Notulae Entomologicae},
	volume = {50},
	year = {1970},
	pages = {41-60},
	author = {Hackman, Walter}
}
@article {22133,
	title = {Three new species of the Allodia lugens group from Northern Europe (Dipt., Mycetophilidae)},
	journal = {Annales Entomologici Fennici},
	volume = {37},
	number = {1},
	year = {1971},
	pages = {3-7},
	author = {Hackman, Walter}
}
