pratiyogee pareekshaon mein saamaany gyaan kee badhatee upayogita tatha baajaar mein isakee maang ko dekhate hue vee end es pablishars ne saamaany gyaan itihaas pustak prakaashit kiya hai. saamaany gyaan itihaas par aadhaarit is pustak mein itihaas se jude samagr tathyon tatha pramukh ghatanaon kee vistrt charcha kee gaee hai. is baat ka bhee dhyaan rakha gaya hai ki pratibhaagiyon ko is vishay mein kisee any pustak kee aavashyakata mahasoos nahin...