amb rian ▁age ) ▁in ▁north - western ▁Spain ▁and ▁northern ▁Portugal , ▁the ▁Pedro ches ▁b athol ith , ▁the ▁, ▁the ▁South - Port ug uese ▁Zone , ▁the ▁Nar ce a ▁series ▁and ▁the ▁West ▁Ast ur ian – Le on ese ▁zone . ▁ ▁References ▁ ▁Cit ations ▁ ▁Bibli ography ▁▁▁▁▁ ▁Category : Ge ology ▁of ▁the ▁I ber ian ▁Pen ins ula <0x0A> </s> ▁Public ▁library ▁advoc acy ▁is ▁support ▁given ▁to ▁a ▁public ▁library ▁for ▁its ▁financial ▁and ▁philosoph ical ▁goals ▁or ▁needs . ▁ ▁Most ▁often ▁this ▁takes ▁the ▁form ▁of ▁mon et ary ▁or ▁material ▁don ations ▁or ▁campaign ing ▁to ▁the ▁institutions ▁which ▁over see ▁the ▁library . ▁ ▁Origin ally , ▁library ▁advoc acy ▁was ▁centered ▁on ▁the ▁library ▁itself , ▁but ▁current ▁tr ends ▁show ▁libraries ▁position ing ▁themselves ▁to ▁demonstrate ▁they ▁provide ▁" e conom ic ▁value ▁to ▁the ▁community ." ▁ ▁History ▁ ▁Form s ▁ ▁Let ter - writing ▁campaign s ▁Let ter ▁writing ▁campaign s ▁are ▁chief ly ▁intended ▁to ▁inform ▁law ▁mak ers , ▁library ▁officials , ▁and ▁citizens ▁about ▁the ▁ram ifications ▁of ▁dec isions ▁regarding ▁public ▁libraries ▁and ▁to ▁promote ▁library - related ▁causes . ▁ ▁Let ter ▁writing ▁has ▁been ▁a ▁valuable ▁form ▁of ▁communication ▁among ▁public ▁library ▁advoc ates . ▁ ▁A ▁well - tim ed ▁and ▁hand - craft ed ▁email ▁or ▁strateg ically ▁sent ▁letter ▁can ▁be ▁a ▁pot ent ▁mechanism ▁used ▁to ▁s way ▁the ▁dec isions ▁of ▁elected