Collins Bird Guide
Collins Field Guide - Birds of the Palearctic: Non-Passerines
Collins Field Guide - BIRDS OF THE PALEARCTIC: Passerines: Passerines (Collins Field Guide)
Austria (Lonely Planet Country Guides)
DK Eyewitness Travel Guide: Austria
Walking in Austria: 100 Mountain Walks in Austria (Cicerone Guides)
Walking Austria's Alps: Hut to Hut
Mountain Walking in Austria (Cicerone guides)
Bulgaria (Lonely Planet Country Guides)
The Rough Guide to Bulgaria (Rough Guide Travel Guides)
DK Eyewitness Travel Guide: Bulgaria
Walking in Bulgaria's National Parks: Pirin, Rila and Central Balkans National Parks (Cicerone Guides)
The Mountains of Bulgaria: A Walker's Companion
Bulgaria Map (Ravenstein International Maps)