▁over look ed ▁in ▁favor ▁of ▁a ▁deep ened ▁concentration ▁on ▁other ▁traditional ▁occup ational ▁tasks ▁such ▁as ▁catalog ing ▁and ▁reference . ▁V os per ▁felt ▁that ▁it ▁was ▁important ▁to ▁step ▁away ▁from ▁the ▁purely ▁mechanical ▁aspects ▁of ▁ac quis itions ▁in ▁favor ▁of ▁using ▁individuals ▁interested ▁in ▁the ▁subject ▁matter ▁of ▁the ▁books ▁in ▁question . ▁This ▁was ▁a ▁directive ▁that ▁V os per ▁pract iced ▁in ▁both ▁his ▁professional ▁career ▁as ▁a ▁library ▁director ▁and ▁as ▁a ▁professor ▁in ▁the ▁field . ▁ ▁Another ▁aspect ▁of ▁li br ari ans hip ▁that ▁V os per ▁worked ▁to ▁improve ▁was ▁in ▁the ▁area ▁of ▁interactions ▁between ▁libraries ▁on ▁an ▁international ▁level . ▁During ▁the ▁Mc Car thy ▁era of ▁the ▁ 1 9 5 0 s , ▁V os per ▁became ▁known ▁both ▁nation ally ▁and ▁intern ation ally ▁as ▁a ▁member ▁of ▁the ▁library ▁profession ▁willing ▁to ▁stand ▁up ▁for ▁intellectual ▁fre ed oms . ▁T ogether ▁with ▁the ▁Chan cell or ▁of ▁the ▁University ▁of ▁Kansas , ▁Franklin ▁D . ▁Mur phy , ▁V os per ▁helped ▁to ▁create ▁an ▁intern ation ally ▁known ▁exhib it ▁on ▁intellectual ▁freedom . ▁The ▁exhib it ' s ▁catalog ▁became ▁so ▁well ▁known ▁and ▁popular ▁that ▁ 2 0 , 0 0 0 ▁copies ▁had ▁to ▁be ▁printed . ▁ ▁In ▁ 1 9 6 4 , ▁V os per ▁wrote ▁for ▁the ▁professional ▁journal ▁Library ▁Tr ends ▁on ▁the ▁status ▁and ▁develop ments ▁of ▁European ▁university ▁libraries . ▁He ▁exam