Stratford- Upon Avon any-three combo- ticket

I'd never heard of that so I googled it. Apparently it is available from at least City HoHo bus Sightseeing and Viator, in both a 24 hour and a 48 hour version. I don't know if the Viator tour is on the City bus or somebody else, I didn't follow it up. But there is is plenty of information online.

If the book gives details perhaps you could follow the link there.

The Tourist Information office is the central location for buying the 3-site ticket, not sold at the individual sites. But a couple of different references indicate that the single-site and 5-site tickets are good for unlimited visits within a year! So I would not worry about the 3-site version being more limited. See also:

Shakespeare Birthplace Trust

TI site page for Anne Hathaway's Cottage

BUT, those purchased from the bus/tour company in combination with a hop-on-hop-off bus ticket are limited to just one visit to each site, again within a year, according to this TripAdvisor review:

"Visited Stratford upon Avon last Summer & bought a combination ticket on the tour bus (a 24hour bus ticket & a Shakespeare 5 houses ticket) Only managed to visit Anne Hathaway's cottage & Mary Arden's farm but the 5 houses ticket is valid for 12 months so I looked forward to returning to see the other 3 houses.Returned to Stratford last week & saw the other 3 houses & decided to go back to Anne Hathaway's cottage for another visit.It was pointed out to me that a 3 or 5 houses ticket purchased on the tour bus entitles you to ONE visit only per house even though valid for 12 months.If you want to re-visit any of the houses you have to pay.This is why the ticket is cheaper to buy than at the Shakespeare centre or the tourist information centre.Tickets purchased there allow unlimited access for 12 months to all the houses.The tour bus is a great way to see the sights with 14 stops of interest that lasts around 60 minutes.You can hop on & hop off as many times as you wish.If you only want to visit the houses once then the combination bus ticket is fine but if you want to re-visit don't buy on the bus as this ticket doesn't cover repeat visits."

We enjoyed the HoHo bus very much, but I'd like to mention that it can take much longer than 60 minutes if there's traffic in town. The day we were there, the bus departure was delayed almost an hour because of traffic, and then our progress along the route was also significantly slower than it would have been without traffic. The slow pace allowed us more time to see sights from the bus, but combined with the initial delay it meant we didn't have time to "hop off" at all. If you want to make use of your combo-ticket, allow plenty of time to get from one place to the next.

Thank you all for your information. We considered taking the HoHo bus but since we are tight on time it probably won’t work for us. We will have a car so will try to get to Mary Arden’s Farm, Anne Hathaway’s Cottage and Shakespeare’s Birthplace but need to do that over two days, so happy to hear that the three combo ticket is good for more than one day.

Most of the things worth seeing are within walking distance of each other, in the core town area. The exception is the Hathaway farm. We saw everything we needed to see on the Town walking tour (<£10) within a few hours. The birthplace museum is not that big. I can't see how a HOHO bus would be needed.

We used the HoHo bus to get around to all five of the Shakespeare sites. Two of the sites are not walking distance from the city.

We very much enjoyed doing the Shakespeare sites, all five of them. The city still has a lot of its historical buildings and we enjoyed it very much. Yes, there were a fair number of tourists there, but why not, it is a major draw for tourists.