Spetsialist - biblioteka - bibliografii︠a︡ : Ogyt issledovanii︠a︡ professionalʹnykh potrebnosteĭ v informatsii /
Gastfer, Mikhail Pavlovich.
Gosudarstvennai︠a︡ publichnai︠a︡ biblioteka imeni M.E. Saltykova-Shchedrina.
Moskva :  Kniga, 
1971.
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