import requests
import wikipedia

def get_summary(topic):
    try:
        return wikipedia.summary(topic, sentences=3)
    except:
        url = "https://en.wikibooks.org/w/api.php"
        params = {
            "action": "query",
            "format": "json",
            "prop": "extracts",
            "titles": topic,
            "exintro": True,
            "explaintext": True
        }
        resp = requests.get(url, params=params).json()
        pages = resp["query"]["pages"]
        for page in pages.values():
            return page.get("extract", None)
    return None